Thursday, January 28, 2021

2020 NFL Game Predictions: Super Bowl, Playoffs, Best Team

Welcome!  I intend this to be an ongoing project of predicting NFL game outcomes, point spreads, and final scores.  My hope is that my models will improve over time as they become more sophisticated and use better data.  I will try to regularly publish predictions to keep myself accountable, and will make observations along the way about what is working and what isn't.  See below for latest updates.  Enjoy!




Previous 2020 Predictions:
________________________________
Recap:
0-1 (LR) with 0.52 expected; 0-1 (RF) with 0.52 expected.  Both models were wrong, I was wrong, and 538 splits.  Don't bet against Tom Brady.  Buccaneers soundly defeat the Chiefs, playing in their home stadium, 31-9.  Don't bet against Tom Brady.  

The season is over so its time for the season recap!
________________________________
Super Bowl:
Here we are at the end: the Super Bowl, with the Chiefs playing the Buccaneers.

The Chiefs have a repeat appearance from last year's Super Bowl victory.  They had the best record in the regular season and have been consistently judged by my models to be the best team in the league. They have always been the #1 seed in my playoff predictions and have always been picked to win the Super Bowl.  They certainly deserve to be here.

The Buccaneers under Tom Brady struggled in the middle of the season.  Before their bye in week 13 they were 7-5.  However, they won 4 straight to finish 11-5 with a Wild Card 5th seed and have been winning ever since, knocking off the Saints and Packers on their way.  They have also climbed in my model's estimation.  They started Week 14 as the predicted #6 seed getting knocked out in the Wild Card round, with a ranking of 15th in the league.  By Week 17 they were the predicted 5th seed progressing to the Division round before losing as 13th in the league.  They moved to 8th in Wild Card week, 9th in Division week, and 6th in Conference week as they continued to win again and again.  What rank are they going into the Super Bowl?  See below.

So who will win?

Oddities and Bold Predictions:
  • Chiefs vs. Buccaneers
    • Both models pick the Chiefs.  538 QB chooses the Chiefs while the 538 traditional model chooses the Buccaneers.  The Chiefs won the last matchup in late November, 27 to 24.  I know I'm not supposed to bet against Tom Brady, but I am picking the Chiefs.
Good luck!

Here are the predictions for the Super Bowl:



Playoffs:

How will the playoffs playout using the final seeding and game results?  Using the LR model for one-time head-to-head matchup predictions:
  • Wildcard:
    • AFC
      • Chiefs (1)-bye
      • Bills (2) vs. Colts (7) -> Bills (2)
      • Steelers (3) vs. Browns (6) -> Browns (6)
      • Titans (4) vs. Ravens (5) -> Ravens (5)
    • NFC
      • Packers (1)- bye
      • Saints (2) vs. Bears (7) -> Saints (2)
      • Seahawks (3) vs. Rams (6) -> Rams (6)
      • Washington (4) vs. Buccaneers (5) -> Buccaneers (5)
  • Division:
    • AFC
      • Chiefs (1) vs. Browns (6) -> Chiefs (1)
      • Bills (2) vs. Ravens (5) ->  Bills (2)
    • NFC
      • Packers (1) vs. Rams (6) -> Packers (1)
      • Saints (2) vs. Buccaneers (5) -> Buccaneers (5)
  • Conference:
    • AFC: Chiefs (1) vs. Bills (2) -> Chiefs (1)
    • NFC: Packers (1) vs. Buccaneers (5) -> Buccaneers (5)
  • Super Bowl:
    • Chiefs (1) vs. Buccaneers (5) -> Chiefs (1) - (0.523)

The LR model still predicts that the Chiefs will go all the way and win the Super Bowl, but obviously its now against the Buccaneers. No need to run a Monte Carlo simulation this week as it would only tell us that the Chiefs have a 52.3% chance of winning the Super Bowl compared with the Buccaneer's 47.7% chance, with everyone else at a 0% chance.

Best Team:
What is the "best" team this week?  If each team were to play every other team once, which team would have the most wins?  By summing up the probabilities of each game matchup, the 32 game season would have a final top 5 rank of:
  1. Chiefs
  2. Packers
  3. Bills
  4. Buccaneers
  5. Saints
Packers move back down to 2 from 1 as Chiefs reclaim the top position.  Bills remain at 3.  Buccaneers jump to 4 from 6.  Saints move to 5 from 7.  Seahawks move to 6 from 4.  Colts move to 8 from 5.  The top 10 has become significantly more competitive as the Chiefs drop below 23 games to 22.955 expected. The Dolphins at 10 are at 19.692 expected wins.  Ranks 3 - 5 round to 21 games and 6 - 10 round to 20 games.  So the field is very close together in predicted wins.

By summing the outcome of each game matchup (1 point per win), the final top 5 rank would be:
  1. Chiefs
  2. Buccaneers
  3. Packers
  4. Bills
  5. Browns
Chiefs stay on top.  Buccaneers move from 4 to 2.  Packers slide to 3 from 2.  Bills move to 4 from 3.  Browns remain at 5.  Interestingly and for the first time, we have some ties, as the Titans tie the Seahawks for 6th and the Dolphins tie the Colts for 8th.  This is possible because:
  • Seahawks beat the Titans but lose to the Colts
  • Titans beat the Colts but lose to the Seahawks
Similarly:
  • Dolphins beat the Colts but lose to the Seahawks
  • Colts lose to the Dolphins but beat the Seahawks
I guess the transitive property doesn't hold (i.e., if A beats B and B beats C, then A beats C).

At this point, it looks like we have 4 top teams: the Chiefs, Packers, Bills, and Buccaneers.  Two of those teams are in the Super Bowl and the other two lost in the Conference Championships, so the playoffs are at least matching this ranking pretty well.

The Chiefs are at the top of both lists and get the number 1 spot.  Packers are ahead of the Bills in both lists as well.  So the Buccaneers are the variable as they win lots of games narrowly while the Packers and Bills win fewer games but with a wider margin on average.  So who is better?  Of just those top 4 teams, the Chiefs win against the others (3), the Buccaneers win 2 (Packers-0.532 and Bills-0.53), the Packers win 1 (against the Bills-0.51), and the Bills win 0.  The Packers have a 0.625 expected value margin on the Buccaneers while the Bills have a 0.277 expected value margin.

One can average the rankings and thereby split the difference between the two rankings, meaning that the Chiefs take first, the Packers take second, but the Buccaneers take third with the Bills moving into fourth.  This seems to be a fair compromise.  But in any case, it seems that the Chiefs are on top, with the Packers/Buccaneers likely fighting for second and third, and with the Bills in fourth.

We'll see if that remains true after this final game...


Tuesday, January 19, 2021

2020 NFL Game Predictions: Conference Championships, Playoffs, Best Team

Welcome!  I intend this to be an ongoing project of predicting NFL game outcomes, point spreads, and final scores.  My hope is that my models will improve over time as they become more sophisticated and use better data.  I will try to regularly publish predictions to keep myself accountable, and will make observations along the way about what is working and what isn't.  See below for latest updates.  Enjoy!




Previous 2020 Predictions:
_______________________________________________________
Recap:
1-1 (LR) with 1.05 expected; 0-2 (RF) with 1.078 expected.  Buccaneers upset the Packers but Chiefs beat the Bills as expected.  Tom Brady gets to go to the Super Bowl again.  I guess the lesson now is not so much "don't bet against the Patriots" but "don't bet against Tom Brady".  Personally disappointed that the Packers lost but glad that the Chiefs made it through.
  • Packers vs. Buccaneers
    • Buccaneers scored first, Packers tied, but Buccaneers took the lead again and never let go.  Everyone misses.
  • Chiefs vs. Bills
    • Bills were up 9-0, but Chiefs got 3 consecutive touchdowns and never lost the lead.  LR, myself, 538 correct; RF incorrect.
On to the Super Bowl!
_______________________________________________________
Conference Championships:
Four teams left as we move to the conference championships: Chiefs vs. Bills, Packers vs. Buccaneers.  Two games this week.  The models disagree on 1 of the 2 games.  538 is in agreement between QB and traditional models.  It sides with LR on both games.

Oddities and Bold Predictions:
  • Chiefs vs. Bills
    • LR picks the Chiefs and RF barely picks the Bills.  538 picks the Chiefs.  A major factor in this is whether or not the Chiefs' top QB will be starting after sustaining a concussion.  The models currently assume he will be playing.  I pick the Chiefs if their top QB does play.  If not, I'm not sure....
  • Packers vs. Buccaneers
    • All models pick the Packers.  I agree: Packers will win.
Good luck!

Here are the predictions for the Conference Championships:



Playoffs:

How will the playoffs playout using the final seeding and game results?  Using the LR model for one-time head-to-head matchup predictions:
  • Wildcard:
    • AFC
      • Chiefs (1)-bye
      • Bills (2) vs. Colts (7) -> Bills (2)
      • Steelers (3) vs. Browns (6) -> Browns (6)
      • Titans (4) vs. Ravens (5) -> Ravens (5)
    • NFC
      • Packers (1)- bye
      • Saints (2) vs. Bears (7) -> Saints (2)
      • Seahawks (3) vs. Rams (6) -> Rams (6)
      • Washington (4) vs. Buccaneers (5) -> Buccaneers (5)
  • Division:
    • AFC
      • Chiefs (1) vs. Browns (6) -> Chiefs (1)
      • Bills (2) vs. Ravens (5) ->  Bills (2)
    • NFC
      • Packers (1) vs. Rams (6) -> Packers (1)
      • Saints (2) vs. Buccaneers (5) -> Buccaneers (5)
  • Conference:
    • AFC: Chiefs (1) vs. Bills (2) -> Chiefs (1) - (0.522)
    • NFC: Packers (1) vs. Buccaneers (5) -> Packers (1) - (0.528)
  • Super Bowl:
    • Chiefs (1) vs. Packers (1) -> Chiefs (1) - (0.510)

The LR model still predicts that the Chiefs will go all the way and win the Super Bowl against the Packers.  No changes in game outcomes in Conference Championships or Super Bowl.

If we run this as a Monte Carlo simulation with the seeding fixed, played games fixed, and 50,000 runs, we get the following result:



Chiefs are still on top but are practically tied with the Packers like last week.  Bills stay at third and Buccaneers are fourth still, but are a much closer fourth than last week after beating the Saints.

Best Team:
What is the "best" team this week?  If each team were to play every other team once, which team would have the most wins?  By summing up the probabilities of each game matchup, the 32 game season would have a final top 5 rank of:
  1. Packers
  2. Chiefs
  3. Bills
  4. Seahawks
  5. Colts
Packers take over the top position (from 2) as Chiefs slide to 2 from 1.  Bills stay at 3. Seahawks surprisingly jump to 4 (from 7), and Colts move to 5 (from 10).  Buccaneers move from 9 to 6, Saints move from 5 to 7, and Titans move from 4 to 8.  I should note that the difference between the Seahawks at 4 and the Steelers at 10 is less than a single game.  While slight changes in the probabilities are dramatically changing the ordering, there are very few if any major differences in the quality of these teams as 5 of the 7 would round to the same number of games won (i.e., 21).

By summing the outcome of each game matchup (1 point per win), the final top 5 rank would be:
  1. Chiefs
  2. Packers
  3. Bills
  4. Buccaneers
  5. Browns
Chiefs remain on top.  Packers move to 2 (from 3).  Bills move back to 3 (from 2).  Buccaneers stay at 4.  Browns move up to 5 (from 12).  Titans move to 8 (from 5).  

For the top three teams, the expected value and total win ranks are largely in agreement. However, the Packers are moving up from fighting with the Bills for second, to fighting with the Chiefs for first.  Although the Packers have a slight expected value advantage over the Chiefs, the model still predicts that the Chiefs would beat the Packers in a matchup.  So we have Chiefs and Packers for first/second, and Bills for third.




Tuesday, January 12, 2021

2020 NFL Game Predictions: Division, Playoffs, Best Team

Welcome!  I intend this to be an ongoing project of predicting NFL game outcomes, point spreads, and final scores.  My hope is that my models will improve over time as they become more sophisticated and use better data.  I will try to regularly publish predictions to keep myself accountable, and will make observations along the way about what is working and what isn't.  See below for latest updates.  Enjoy!




Previous 2020 Predictions:

_______________________________________________________
Recap:
4-0 (LR) with 2.345 expected; 2-2 (RF) with 2.319 expected.  I personally went 3-1, as did 538.  LR got lucky and RF got unlucky.
  • Bills beat the Ravens as predicted.  All models except RF correct.
  • Packers solidly beat the Rams.  All models correct.
  • Chiefs beat the Browns, holding on to the lead after losing their starting QB to a concussion.  All models correct.  Whether the QB will play in the next game will be a huge factor in the Chiefs' likelihood of winning that game.
  • Buccaneers upset the Saints as LR is correct; everyone else is incorrect.
Next week is the Conference Championships!
_______________________________________________________
Division:
The Wild Card week is done and we are on to the Divisional round.  The winners of the Wild Card games play each other and the #1 seeds that had a first round bye.  There are 4 games this week.  

The models disagree on 2 of the 4 games.  538 is in agreement between QB and traditional models.  It sides with LR on 1 game and RF on another.  All models are in agreement on 2 games.  So not a straightforward week for predictions.  I'd expect to only get 2 games right.

Oddities and Bold Predictions:
  • Bills vs. Ravens
    • LR picks Bills but RF picks Ravens.  538 (QB and traditional) chooses the Bills.  Bills are 14-3 and Ravens are 12-5.  Bills play at home.  I think this is a pretty good matchup with pretty evenly matched teams, so it could go either way.  I am going to side with the Bills.
  • Packers vs. Rams
    • All models agree: Packers will win.  I am inclined to agree.
  • Saints vs. Buccaneers
    • LR picks Buccaneers but RF picks Saints.  538 (QB and traditional) picks Saints.  Saints play at home and are 13-4.  Buccaneers are 12-5.  Both teams are passing teams and the stats are very similar so it's a close call.  Buccaneers lost both previous matchups this season.  Picking the Saints.
  • Chiefs vs. Browns
    • All models agree: Chiefs will win.  Picking the Chiefs.
Good luck!

Here are the predictions for the Divisional Round:



Playoffs:

How will the playoffs playout using the final seeding and game results?  Using the LR model for one-time head-to-head matchup predictions:
  • Wildcard:
    • AFC
      • Chiefs (1)-bye
      • Bills (2) vs. Colts (7) -> Bills (2)
      • Steelers (3) vs. Browns (6) -> Browns (6)
      • Titans (4) vs. Ravens (5) -> Ravens (5)
    • NFC
      • Packers (1)- bye
      • Saints (2) vs. Bears (7) -> Saints (2)
      • Seahawks (3) vs. Rams (6) -> Rams (6)
      • Washington (4) vs. Buccaneers (5) -> Buccaneers (5)
  • Division:
    • AFC
      • Chiefs (1) vs. Browns (6) -> Chiefs (1) - (0.56)
      • Bills (2) vs. Ravens (5) ->  Bills (2) - (0.618)
    • NFC
      • Packers (1) vs. Rams (6) -> Packers (1) - (0.661)
      • Saints (2) vs. Buccaneers (5) -> Buccaneers (5) - (0.506)
  • Conference:
    • AFC: Chiefs (1) vs. Bills (2) -> Chiefs (1) - (0.512)
    • NFC: Packers (1) vs. Buccaneers (5) -> Packers (1) - (0.526)
  • Super Bowl:
    • Chiefs (1) vs. Packers (1) -> Chiefs (1) - (0.525)

The LR model still predicts that the Chiefs will go all the way and win the Super Bowl against the Packers.

If we run this as a Monte Carlo simulation with the seeding fixed, played games fixed, and 20,000 runs, we get the following result:



The Chiefs still win most often at 17.8% (down from 20%), followed by the Packers at 17.6% (up from 16%), so they are virtually tied.  The Bills, having won in the first round, are now at 16.8% (up from 9%).  All of the teams that played and won in the first round have a boost in likelihood as they now distribute among themselves the collective probabilities once assigned to their Wild Card opponents.  Also, the advantage once given to the Chiefs and Packers due to their having first round byes no longer applies, meaning that the probabilities given now better reflect only the strength of each team as measured by the model (as well as matchup advantages/disadvantages due to seeding).

Best Team:
What is the "best" team this week?  If each team were to play every other team once, which team would have the most wins?  By summing up the probabilities of each game matchup, the 32 game season would have a final top 5 rank of:
  1. Chiefs
  2. Packers
  3. Bills
  4. Titans
  5. Saints
Chiefs remain on top. Packers move from 5 to 2.  Bills move from 2 to 3.  Steelers get bumped from 3 to 8.  Seahawks get bumped from 4 to 7.  Titans move up to 4 from 13.  Saints move up from 7 to 5.  Ravens move from 9 to 6.  Buccaneers move from 8 to 9, Browns from 6 to 12, and Rams from 14 to 13.  

By summing the outcome of each game matchup (1 point per win), the final top 5 rank would be:
  1. Chiefs
  2. Bills
  3. Packers
  4. Buccaneers
  5. Titans
Chiefs stay on top.  Bills remain in second. Packers move from 4 to 3.  Buccaneers move from 5 to 4.  Steelers move from 3 to 7.  Titans move from 11 to 5.  Saints move from 9 to 6.  Ravens move from 12 to 9.  Browns move from 7 to 12.  Rams move from 14 to 13.  

For the top three teams, the expected value and total win ranks are largely in agreement.  In short, the Chiefs still remain the "best" team with the Bills and Packers fighting it out for second and third.



Tuesday, January 5, 2021

2020 NFL Game Predictions: Wild Card, Playoffs, Best Team

Welcome!  I intend this to be an ongoing project of predicting NFL game outcomes, point spreads, and final scores.  My hope is that my models will improve over time as they become more sophisticated and use better data.  I will try to regularly publish predictions to keep myself accountable, and will make observations along the way about what is working and what isn't.  See below for latest updates.  Enjoy!




Previous 2020 Predictions:
________________________________________________________
Recap:
3-3 (LR) with 3.406 expected; 5-1 (RF) with 3.548 expected.  With those probabilities, I had a 52% chance of getting 3 or fewer games correct with the LR model, so not surprising.  I think I got lucky with the RF model.  Personally, I go 4-2.  538 QB is 4-2 and 538 traditional is 3-3.
  • Bills beat the Colts.  Colts scored first but Bills took lead late in 1st quarter and never gave it up.  Everybody correct. 
  • Rams beat the Seahawks.  Rams scored first, Seahawks tied, but Rams took lead again and never gave it up.  Several interceptions and dropped passes by the Seahawks as the Rams decisively win over the Seahawks.  Everybody incorrect.
  • Buccaneers beat Washington.  Buccaneers took and never lost the lead.  Everybody correct.  
  • Ravens beat Titans.  Titans took early lead but Ravens tied it by the half.  Ravens took lead in 3rd quarter and never lost it after that.  RF, 538 QB, and myself correct; LR and 538 traditional incorrect.
  • Saints beat the Bears as expected.  Saints took and never lost the lead.  Everybody correct.
  • Browns beat the Steelers.  Browns took 28-0 lead in first quarter with a missed Steelers snap turned into a Browns touchdown and several interceptions.  Steelers closed in to 11 points by the end of the game but never caught up.  Lots of scoring for a final 48-37 Browns victory in which Steelers QB throws for 501 yards but 4 interceptions.  RF correct; LR, myself, 538 QB, and 538 traditional incorrect.
Playoff predictions are hard.  Better and more evenly matched teams mean that the probabilities are closer together, making any prediction more like a 50-50 guess.  I suppose that is good as it makes for an exciting playoff experience.

On to the divisional round!
________________________________________________________
Wild Card:
At last we are in the playoffs with the Wild Card round.  Seeds 2-7 face off while the number 1 seeds have a bye.  There are 6 games this week.  The models disagree on 2 of the 6 games.  538 is split on one of those as well.  Here we go...

Oddities and Bold Predictions:
  • Steelers vs. Browns
    • LR favors Steelers while RF picks Browns.  538 (QB and traditional) picks Steelers.  The Browns and Steelers just played, and though the Browns won, they won barely, and the Steelers were sitting a lot of their starters.  Steelers play at home.  Steelers are 12-4 and Browns are 11-5.  Picking the Steelers.
  • Titans vs. Ravens
    • LR narrowly picks Titans while RF narrowly picks Ravens.  538 QB picks Ravens while 538 traditional picks Titans.  So this is a toss up.  Titans play at home and are 11-5.  Ravens are also 11-5.  Titans won the previous matchup this season.  Ravens look like a slightly better team on paper.  Picking the Ravens.
The other predictions look correct, but I have a funny feeling about the Colts upsetting the Bills... Good luck!

Here are the predictions for Wild Card Week:



Playoffs:
The playoff seeds are now fixed as follows:
  • AFC
    1. Chiefs: West Champ
    2. Bills: East Champ
    3. Steelers: North Champ
    4. Titans: South Champ
    5. Ravens: Wild Card #1
    6. Browns: Wild Card #2
    7. Colts: Wild Card #3
  • NFC
    1. Packers: North Champ
    2. Saints: South Champ
    3. Seahawks: West Champ
    4. Washington: East Champ
    5. Buccaneers: Wild Card #1
    6. Rams: Wild Card #2
    7. Bears: Wild Card #3
How good were my playoff predictions?  I started predicting playoffs in week 14.  So there are 4 weeks of playoff seed predictions.  These are the summary results:
  • Week 14:
    • Made Playoffs: AFC - 6/7; NFC - 5/7
    • Correct Seed: AFC - 2/7; NFC - 0/7 
  • Week 15:
    • Made Playoffs: AFC - 6/7; NFC - 6/7
    • Correct Seed:  AFC - 2/7; NFC - 3/7
  • Week 16:
    • Made Playoffs: AFC - 6/7; NFC - 6/7
    • Correct Seed: AFC - 2/7; NFC - 4/7
  • Week 17:
    • Made Playoffs: AFC - 6/7; NFC - 7/7
    • Correct Seed: AFC - 5/7; NFC - 7/7
The consistent misses in making the playoffs were the Dolphins in the AFC and the Cardinals in the NFC, but overall this was not too challenging.  The correct seeding is much more difficult.  Seeds #1-4 remained largely the same, but the ordering of #5-7 changed nearly every week.

How will the playoffs playout using the final seeding and game results?  Using the LR model for one-time head-to-head matchup predictions:
  • Wildcard:
    • AFC
      • Chiefs (1)-bye
      • Bills (2) vs. Colts (7) -> Bills (2) - (0.528)
      • Steelers (3) vs. Browns (6) -> Steelers (3) - (0.521)
      • Titans (4) vs. Ravens (5) -> Titans (4) - (0.509)
    • NFC
      • Packers (1)- bye
      • Saints (2) vs. Bears (7) -> Saints (2) - (0.681)
      • Seahawks (3) vs. Rams (6) -> Seahawks (3) - (0.631)
      • Washington (4) vs. Buccaneers (5) -> Buccaneers (5) - (0.536)
  • Division:
    • AFC
      • Chiefs (1) vs. Titans (4) -> Chiefs (1) - (0.613)
      • Bills (2) vs. Steelers (3) ->  Bills (2) - (0.513)
    • NFC
      • Packers (1) vs. Buccaneers (5) -> Packers (1) - (0.507)
      • Saints (2) vs. Seahawks (3) -> Seahawks (3) - (0.53)
  • Conference:
    • AFC: Chiefs (1) vs. Bills (2) -> Chiefs (1) - (0.539)
    • NFC: Packers (1) vs. Seahawks (3) -> Packers (1) - (0.51)
  • Super Bowl:
    • Chiefs (1) vs. Packers (1) -> Chiefs (1) - (0.559)

The LR model still predicts that the Chiefs will go all the way and win the Super Bowl against the Packers.  In fact, the outcomes are the exact same as the predictions from last week.  There are slight probabilistic changes, but the predicted winner of each game in the playoffs is the same.

If we run this as a Monte Carlo simulation with the seeding fixed and 20,000 runs, we get the following result:



The Chiefs still win most often at 20% of the time (down from 24%), followed by the Packers at 16% (down from 20%) and the Bills at 9% (stay the same).  The downward change in the Chiefs is most likely due to sitting their starters and losing their last game.  We know that this doesn't really reflect how good the team is, but the model doesn't know that.  The previous 24% is probably a better reflection of the Chief's chances of winning the Super Bowl.

Best Team:
What is the "best" team this week?  If each team were to play every other team once, which team would have the most wins?  By summing up the probabilities of each game matchup, the 32 game season would have a final top 5 rank of:
  1. Chiefs
  2. Bills
  3. Steelers
  4. Seahawks
  5. Packers
Chiefs remain on top. Bills remain in second.  Steelers move from 8 to 3.  Packers move from 3 to 5.  Seahawks move from 5 to 4.   Saints move from 4 to 7.  In all this, it is important to remember that only the Chiefs are ahead of the next team by a full game.  In fact, the difference between the Bills and the Saints is only 1.37 games.  A very slight change in the probabilities can significantly change the ordering of the top teams, as it continues to do so.

By summing the outcome of each game matchup (1 point per win), the final top 5 rank would be:
  1. Chiefs
  2. Bills
  3. Steelers
  4. Packers
  5. Buccaneers
Chiefs stay on top.  Bills remain in second. Steelers move from 4 to 3.  Packers move from 3 to 4.  Buccaneers jump from 11 to 5.  Seahawks remain at 6.  Dolphins move from 4 to 10.

For the top three teams, the expected value and total win ranks are in agreement.  In short, the Chiefs still remain the "best" team, the Bills remain in second, and the Steelers move up to third.

Wednesday, December 30, 2020

2020 NFL Game Predictions: Week 17, Playoffs, Best Team

Welcome!  I intend this to be an ongoing project of predicting NFL game outcomes, point spreads, and final scores.  My hope is that my models will improve over time as they become more sophisticated and use better data.  I will try to regularly publish predictions to keep myself accountable, and will make observations along the way about what is working and what isn't.  See below for latest updates.  Enjoy!




Previous 2020 Predictions:
________________________________________________________
Recap:
13-3 (LR) with 10.887 expected; 13-3 (RF) with 10.418 expected.  The models did better than expected. Using the LR probabilities, there was about a 19% chance of getting 13 or better games correctly predicted.  538 QB missed 4 while 538 traditional missed 5.  Personally I missed 3.  
  • Raiders did beat Broncos.  My models and myself correct; 538 incorrect.  Broncos lose by 1 in a back and forth game.
  • Rams beat the Cardinals.  My models and 538 traditional correct; 538 QB and myself incorrect.  Cardinals got the first score but never scored again as they miss the playoffs.  Cardinals top QB was injured early in the game, missing a lot of the rest of it and certainly not playing as well as he would have if uninjured.
  • Steelers lose to Browns.  Myself and 538 QB correct; my models and 538 traditional incorrect.  Steelers did not start their top QB to rest him and others for the playoffs.  Browns had a huge lead early in 4th quarter and held on to win despite a comeback by the Steelers.  Browns make it into the playoffs and will be playing the Steelers in the Wild Card round.
  • Washington beats the Eagles.  My models, 538 QB, and myself correct; 538 traditional incorrect.  Washington makes it into the playoffs.
  • Chiefs lose to Chargers.  Everybody incorrect.  Chiefs sat their top QB among other starters in order to rest them for the playoffs, so a loss is not really surprising.
  • Cowboys lose to Giants.  Everybody incorrect.  Giants took the lead early and never gave it up.  Either team potentially had a shot at the playoffs if Washington lost, but Washington won, so both teams miss out.
On to the playoffs!!
________________________________________________________
Week 17:
Happy New Year! This is the last week before the playoffs.  No changes in the models except to retrain them with the latest data. 

The models disagree with each other on 0 games this week, that is, they are in complete agreement.
With 538 QB, there are 3 disagreements, and with 538 traditional, there are 2 disagreements.  16 games this week as no one has a bye.

Oddities and Bold Predictions:
  • Raiders vs. Broncos
    • My models pick the Raiders but 538 (QB and traditional) picks the Broncos.  Broncos play at home and are 5-10.  Raiders are 7-8.  Sticking with the Raiders.
  • Rams vs. Cardinals
    • My models pick the Rams, 538 QB picks the Cardinals, but 538 traditional picks the Rams.  Rams play at home and are 9-6.  Cardinals are 8-7.  Rams are in the playoffs regardless, but Cardinals need to win to get into playoffs.  Rams starting QB is out.  Picking the Cardinals.
  • Steelers vs. Browns
    • My models pick the Steelers, 538 QB picks Browns, but 538 traditional picks Steelers.  Browns play at home and are 10-5.  Steelers are 12-3.  Browns need to win to stay in playoffs.  Browns are pretty beat up but they have more on the line.  Picking the Browns to win.
  • Washington vs. Eagles
    • My models pick Washington, 538 QB picks Washington, but 538 traditional picks the Eagles.  Eagles are 4-10-1 and play at home while Washington is 6-9.  Looks like the Eagles best QB will be playing, and so will the best Washington QB.  Washington is playing to stay in the playoffs while the Eagles don't have any playoff chances.  Sticking with Washington.  
An exciting final week as a lot is still at stake for which teams will get into the playoffs.  Good luck!

Here are the predictions for Week 17:



Playoffs:
Here are the latest predictions using the LR model for who will get to the playoffs. 

The AFC top seed remains with the Chiefs.  Bills stay at #2, but Steelers move from #4 to # 3 with last week's win over the Colts.  Colts drop from #3 to #6 with their loss to the Steelers.  Titans move from #6 to #4 as the South Champ, having a better division win % than the Colts.  Ravens are back in the playoffs at #5 with head to head advantage over Colts.  Dolphins remain at #7 with conference win % advantage over Browns, meaning that Browns drop out of the playoffs.

The NFC top seed remains with the Packers.  Saints remain at #2 with conference win % over Seahawks, and Seahawks remain at #3.  Washington stays at #4 with head to head advantage over Cowboys.  Buccaneers move up from #6 to #5 and Rams move down from #5 to #6.  Bears jump back into playoffs at #7 with win % in common games advantage over Cardinals, meaning that the Cardinals are out of the playoffs.  
  • AFC
    1. Chiefs: West Champ
    2. Bills: East Champ, head to head win over Steelers
    3. Steelers: North Champ
    4. Titans: South Champ, division win % over Colts
    5. Ravens: Wild Card #1, head to head over Colts
    6. Colts: Wild Card #2
    7. Dolphins: Wild Card #3, conference win % over Browns
  • NFC
    1. Packers: North Champ
    2. Saints: South Champ, conference win % over Seahawks
    3. Seahawks: West Champ
    4. Washington: East Champ, head to head over Cowboys
    5. Buccaneers: Wild Card #1
    6. Rams: Wild Card #2
    7. Bears: Wild Card #3, win % in common games over Cardinals


If the foregoing is true (and I did the tiebreaking correctly), how will the playoffs playout?  Using the LR model for one-time head-to-head matchup predictions:
  • Wildcard:
    • AFC
      • Chiefs (1)-bye
      • Bills (2) vs. Dolphins (7) -> Bills (2) - (0.542)
      • Steelers (3) vs. Colts (6) -> Steelers (3) - (0.502)
      • Titans (4) vs. Ravens (5) -> Titans (4) - (0.594)
    • NFC
      • Packers (1)- bye
      • Saints (2) vs. Bears (7) -> Saints (2) - (0.705)
      • Seahawks (3) vs. Rams (6) -> Seahawks (3) - (0.592)
      • Washington (4) vs. Buccaneers (5) -> Buccaneers (5) - (0.527)
  • Division:
    • AFC
      • Chiefs (1) vs. Titans (4) -> Chiefs (1) - (0.643)
      • Bills (2) vs. Steelers (3) ->  Bills (2)- (0.55)
    • NFC
      • Packers (1) vs. Buccaneers (5) -> Packers (1) - (0.59)
      • Saints (2) vs. Seahawks (3) -> Seahawks (3) - (0.511)
  • Conference:
    • AFC: Chiefs (1) vs. Bills (2) -> Chiefs (1) - (0.568)
    • NFC: Packers (1) vs. Seahawks (3) -> Packers (1) - (0.566)
  • Super Bowl:
    • Chiefs (1) vs. Packers (1) -> Chiefs (1) - (0.596)

The LR model still predicts that the Chiefs will go all the way and win the Super Bowl against the Packers.

If we run this as a Monte Carlo simulation with the seeding fixed and 20,000 runs, we get the following result:



The Chiefs still win most often at 24% of the time (down from 25%), followed by the Packers at 20% (up from 18%) and the Bills at 9%.  

Importance of Getting the #1 Seed
How important is getting the #1 seed in the playoffs?  The Bills (see below) are predicted to be a slightly better team than the Packers, and yet, the Packers have an 11% Super Bowl win percentage-point advantage over them.  If I switch the Bills to the #1 seed and the Chiefs to #2 seed, the Bills' probability of a Super Bowl victory increases from 9% to 17% (8 percentage point increase), while the Chiefs' probability decreases from 24% to 14% (10 percentage point decrease).  Likewise, switching the Saints to the #1 seed and the Packers to the #2 seed increases the Saints from 8% to 13% (5 percentage point increase) and decreases the Packers from 20% to 12% (8 percentage point decrease).  If I swap the Bills and the Packers so that the Bills are the #1 seed in the NFC and the Packers are the #2 seed in the AFC, then the Bills have a 20% chance of Super Bowl victory (11 percentage point increase) while the Packers have only an 8% chance (12 percentage point decrease).  That is, they essentially swap percentages!

Getting the #1 seed and a first round bye appears to increase a team's chance of winning the Super Bowl by 8 to 10 percentage points, which amounts to roughly doubling the chances of a Super Bowl victory for that team.  Together, the number #1 seeds have a 44% chance of one of them winning the Super Bowl.  Clearly, getting the #1 seed makes it much more likely that the #1 seeded team will win the Super Bowl.

Perhaps this should not surprise us mathematically.  If we assume each team has a 50% chance of winning any particular game, then a #1 seed has to win 3 games to win the Super Bowl, which gives it a 50% *50% *50% = 12.5% chance of winning.  Seeds 2-7 have to win 4 games, which gives them each a 50% *50% *50%*50% = 6.25% chance.  That is, all other things being equal, a #1 seed has double the chance of winning the Super Bowl that a 2-7 seed has, or a 6.25 percentage point advantage.

This advantage is increased by how good the #1 seed is with respect to the other teams.  For example, we saw that the Packers gain much more from being the #1 seed than the Saints do.  This is because the Packers have an average probability against all teams of 69% (according to LR), whereas the Saints have a 64% average probability.  Thus, for each game played, the Packers get to keep more of their probability towards winning the Super Bowl than the Saints do (i.e., they keep 69% of their likelihood, while the Saints only keep 64%).  With only 3 games, the Packers would have a 0.69^3 = 33% chance of winning the Super Bowl.  The Saints would comparatively have a 0.64^3 = 26% chance.  But the Saints also have to play one additional game, meaning that they only have a 0.64^4 = 17% chance of winning the Super Bowl.  They lose 36% of their likelihood because they have to play an additional game, and would lose even more if they were a worse team.

To recap, getting the #1 seed increases a team's chances of winning the Super Bowl by at least 6.25 percentage points.  Also, the better the #1 seed is compared to the other playoff teams, the greater this advantage is.  Since the #1 seed is guaranteed to be the "best" team in the conference from a wins/loss perspective, the advantage is likely to be significant.  Together, having one fewer game to play combined with being the "best" team in the conference means that the #1 seed has a much greater likelihood of winning the Super Bowl than would occur in a randomized head-to-head matchup playoff system with no team having a bye.  Not to mention that the #1 seed always has home field advantage and always gets to play the lowest ranked seed (i.e., the supposedly "worst" team) available, which is another advantage. 

The playoff system is designed to give the "best" two teams every advantage to get to and win the Super Bowl.  Perhaps this is for the best as we want the "best" team to win the Super Bowl.  But it does also feel like it is perhaps too biased in the #1 seeds' favor as we also want the playoffs to be competitive and to give every playoff team a fair chance to win the Super Bowl.  As shown below, the "best" teams aren't that much better than other teams, and the advantage given to them in the playoffs can feel a bit disproportionate.  "For whoever has, to him more shall be given; and whoever does not have, even what he has shall be taken away from him." (Mark 4:25).  This most certainly is true in the current NFL playoff system, but maybe it is the best compromise of our conflicting desires to have the "best" team win the Super Bowl while still having a competitive playoff system.

Best Team:
What is the "best" team?  If each team were to play every other team once, which team would have the most wins?

By summing up the probabilities of each game matchup, the 32 game season would have a final top 5 rank of:
  1. Chiefs
  2. Bills
  3. Packers
  4. Saints
  5. Seahawks
Chiefs remain on top. Bills move from 6 to 2.  Packers move from 2 to 3.  Seahawks move from 3 to 5.  Saints move up from 7 to 4.  Titans move from 4 to 6.  Colts get pushed from 5 to 7.

By summing the outcome of each game matchup (1 point per win), the final top 5 rank would be:
  1. Chiefs
  2. Bills
  3. Packers
  4. (4) Steelers
  5. (4) Dolphins
Chiefs stay on top.  Bills move from 6 to 2.  Packers move from 2 to 3.  Steelers move from 11 to 4.  Dolphins move from 7 to 4.  Seahawks move from 3 to 6, and Colts move from 4 to 6.

The difference between these two lists is striking this week.  While the top 3 are the same, 4-7 are very different.  The Saints are judged to have the 4th highest expected value of games won, but are 9th in total wins.  This means that the Saints are predicted to win less often, but when they are predicted to win, they are much more likely to win.  This suggests that they match up really well against some teams, but are mediocre against others.  This is in contrast with the Steelers and Dolphins who are ranked lower in expected value, but higher in total wins.  These teams are predicted to win a lot of games, but only barely.  

An extreme of this paradoxical situation would be if a team was predicted to win each game it played with 50.1% probability.  Then in the list below, it would have an expected value of 16.032 games won, placing it in the middle of that list, but a total wins value of 32, placing it at the top of that list.  A team with this sort of probability is obviously not going to win every single game.  Thus, the expected value is probably a much better judge of how good a team is.

For the top three teams, the expected value and total win ranks are in agreement.  In short, the Chiefs still remain the "best" team.  The Bills move up to second and the Packers move down to third.


Thursday, December 24, 2020

2020 NFL Game Predictions: Week 16, Playoffs, Best Team

Welcome!  I intend this to be an ongoing project of predicting NFL game outcomes, point spreads, and final scores.  My hope is that my models will improve over time as they become more sophisticated and use better data.  I will try to regularly publish predictions to keep myself accountable, and will make observations along the way about what is working and what isn't.  See below for latest updates.  Enjoy!




Previous 2020 Predictions:
________________________________________________________
Recap:
 10-6 (LR) with 10.519 expected, and 9-7 (RF) with 9.937 expected.  So the models performed as expected.  I personally go 12-4.  538 QB goes 11-5, 538 traditional goes 12-4.
  • Seahawks beat the Rams.  LR, myself, and 538 get this correct; RF misses this.  Rams got the first score, but Seahawks were able to tie things up by the half and then took the lead without losing it again in the second half.
  • Chargers beat the Broncos.  538 and myself correct; LR and RF incorrect.  Chargers took the lead early, but Broncos came back to tie it up near the end.  Chargers finished the game with a field goal to win.
  • Steelers win against Colts.  538 traditional and myself correct; 538 QB, LR, RF incorrect.  Steelers were down 21-7 at the half.  Steelers got 3 touchdowns in second half to put them over the top 28-24.  
  • 49ers beat Cardinals.  Everyone misses.  Cardinals got the first score, but 49ers quickly took the lead and never let go.
  • Jets upset the Browns by winning their second game.  Everyone misses. Browns scored first but Jets took the lead and then never gave it up.
  • Bengals beat the Texans.  Everyone misses.  Bengals took the lead first but Texans kept tying it up.  Texans even took the lead halfway through the 4th quarter, but Bengals came back with a TD to take the lead and a field goal to cap it off.
  • Panthers beat Washington.  Everyone misses.  Panthers got up 20-3 in the first half, and though they didn't score anymore, they held on to win 20-13.  
On to the last week!
________________________________________________________
Week 16:
Merry Christmas! Two weeks left before the playoffs!  No changes in the models except to retrain them with the latest data.  However, another code update was required to handle some new bad data that was giving incorrect results for starter information.

The models disagree with each other on one game, with 538 on another, and 538 models split on a third.  So pretty consistent this week.

16 games this week as no one has a bye.

Oddities and Bold Predictions:
  • Seahawks vs. Rams
    • LR predicts a Seahawks victory while RF predicts a Rams victory.  538 (QB and traditional) pick Seahawks.  Seahawks play at home and are 10-4, while Rams are 9-5.  Rams won the last matchup in LA.  Rams lost to Jets last week.  Picking the Seahawks.
  • Broncos vs. Chargers
    • LR and RF barely pick Broncos, but 538 (QB and traditional) barely picks Chargers.  Chargers play at home.  Both teams are 5-9.  Broncos won the last matchup by 1 point. Looking at the statistics, Chargers seem to be the better team on paper.  Picking the Chargers.
  • Colts vs. Steelers
    • LR and RF pick Colts.  538 QB adjusted picks Colts as well while 538 traditional picks Steelers.  Steelers play at home and are 11-3.  Colts are 10-4.  Steelers have lost 3 in a row, including last week to the Bengals.  Colts have won the last 3 games.  Looking at the statistics, Colts appear to be the better team, but they also haven't played as strong a schedule as the Steelers.  Hmmm. I could go either way, but I feel like I should pick the Steelers.  I don't think they will lose four in a row...
Good luck!

Here are the predictions for Week 16:



Playoffs:
Here are the latest predictions using the LR model for who will get to the playoffs. 

Changes in AFC include Steelers moving to seed 4 (lost to Bills, predicted loss to Colts), and Bills take second seed.  Colts jump to third seed with a predicted win over Steelers.  Browns remain at seed 5 with head to head win over Titans.  Titans move down to seed 6.  Dolphins remain seed 7 with conference win % advantage over Ravens.

In the NFC, Packers remain on top.  The Saints stay at the second seed with conference win % advantage over Seahawks.  Seahawks jump to third seed.  Washington remains fourth seed.  Rams go to 5th seed with head to head record over Buccaneers.  Buccaneers are 6th seed, and Cardinals remain as 7th seed.
  • AFC
    1. Chiefs: West Champ
    2. Bills: East Champ, head to head win over Steelers
    3. Colts: South Champ, predicted win over Steelers
    4. Steelers: North Champ
    5. Browns: Wild Card #1, head to head over Titans
    6. Titans: Wild Card #2
    7. Dolphins: Wild Card #3
  • NFC
    1. Packers: North Champ
    2. Saints: South Champ, conference win% over Seahawks
    3. Seahawks: West Champ
    4. Washington: East Champ
    5. Rams: Wild Card #1, head to head record over Buccaneers
    6. Buccaneers: Wild Card #2
    7. Cardinals: Wild Card #3

If the foregoing is true (and I did the tiebreaking correctly), how will the playoffs playout?  Using the LR model for one-time head-to-head matchup predictions:
  • Wildcard:
    • AFC
      • Chiefs (1)-bye
      • Bills (2) vs. Dolphins (7) -> Bills (2) - (0.516)
      • Colts (3) vs. Titans (6) ->Colts (3) - (0.512)
      • Steelers (4) vs. Browns (5) -> Browns (5) - (0.526)
    • NFC
      • Packers (1)- bye
      • Saints (2) vs. Cardinals (7) -> Saints (2) - (0.573)
      • Seahawks (3) vs. Buccaneers (6) -> Seahawks (3) - (0.633)
      • Washington (4) vs. Rams (5)-> Washington (4) - (0.510)
  • Division:
    • AFC
      • Chiefs (1) vs. Browns (5)-> Chiefs (1) - (0.632)
      • Bills (2) vs. Colts (3) ->  Colts (3) - (0.513)
    • NFC
      • Packers (1) vs. Washington (4) -> Packers (1) - (0.589)
      • Saints (2) vs. Seahawks (3) -> Seahawks (3) - (0.589)
  • Conference:
    • AFC: Chiefs (1) vs. Colts (3) -> Chiefs (1) - (0.601)
    • NFC: Packers (1) vs. Seahawks (3) -> Packers (1) - (0.513)
  • Super Bowl:
    • Chiefs (1) vs. Packers (1) -> Chiefs (1) - (0.590)

The LR model still predicts that the Chiefs will go all the way and win the Super Bowl, now against the Packers.

If we run this as a Monte Carlo simulation with the seeding fixed and 20,000 runs, we get the following result:



The Chiefs still win most often at 25% of the time, followed by Packers (18%) and Seahawks (10%).


Best Team:
What is the "best" team?  If each team were to play every other team once, which team would have the most wins?

By summing up the probabilities of each game matchup, the 32 game season would have a final top 5 rank of:
  1. Chiefs
  2. Packers
  3. Seahawks
  4. Titans
  5. Colts
Chiefs remain on top.  Packers move up to 2 from 3, Seahawks move from 5 to 3, Saints move down from 2 to 7, Titans stay at 4, and Colts move to 5.

By summing the outcome of each game matchup (1 point per win), the final top 5 rank would be:
  1. Chiefs
  2. Packers
  3. Seahawks
  4. Colts
  5. Titans
Chiefs stay on top.  Packers move from 3 to 2.  Saints move from 2 to 8.  Seahawks move up to 3.  Colts move to 4 and Titans move to 5 from 4.  Washington moves to 12.  

In short, Chiefs still remain the "best" team, with Packers taking second and Seahawks taking third.