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:
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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!
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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.

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