It’s a new playoff season, and another time to try our new playoff formulas. Methodology of this work is described in depth here.
The playoff formulas like New Orleans and Kansas City. They like Baltimore, but Baltimore, which will lose home field after the first round, is unlikely to be favored after that point. The formulas place a substantial penalty on the lack of playoff experience, and so does not favor Chicago, the Chargers, or the Colts. Update: Baltimore has not been in the playoff since 2014, and so the results have been amended.
2017 NFL Playoff Teams, C&F Worksheet. |
NFC |
Rank |
Name |
Home Field Adv |
Playoff Experience |
SOS |
Total Score |
1 |
New Orleans Saints |
0.660 |
0.747 |
0.192 |
1.599 |
2 |
LA Rams |
0.660 |
0.747 |
-0.134 |
1.273 |
3 |
Chicago Bears |
0.660 |
0.0 |
-0.711 |
-0.051 |
4 |
Dallas Cowboys |
0.660 |
0.747 |
0.046 |
1.453 |
5 |
Seattle Seahawks |
0.0 |
0.747 |
-0.170 |
0.577 |
6 |
Philadelphia Eagles |
0.0 |
0.747 |
0.167 |
0.914 |
AFC |
1 |
Kansas City Chiefs |
0.660 |
0.747 |
-0.033 |
1.374 |
2 |
New England Patriots |
0.660 |
0.747 |
-0.535 |
0.872 |
3 |
Houston Texans |
0.660 |
0.747 |
-0.465 |
0.942 |
4 |
Baltimore Ravens |
0.660 |
0 |
0.195 |
0.855 |
5 |
LA Chargers |
0.0 |
0.0 |
-0.070 |
-0.070 |
6 |
Indianapolis Colts |
0.0 |
0.0 |
-0.693 |
-0.693 |
The total score of a particular team is used as a base. Subtract the score of the opponent and the result is the logit of the win probability for that game. You can use the inverse logit (see Wolfram Alpha to do this easily) to get the probability, and you can multiply the logit of the win probability by 7.4 to get the estimated point spread.
Because the worksheet above can be hard to decipher, for the first week of the 2018 playoffs, I’ve done all this for you, in the table below. Odds are presented from the home team’s point of view:
First Round Playoff Odds |
Home Team |
Visiting Team |
Score Diff |
Win Prob |
Est. Point Spread |
Chicago Bears |
Philadelphia Eagles |
-0.965 |
0.276 |
-7.1 |
Dallas Cowboys |
Seattle Seahawks |
0.876 |
0.706 |
6.5 |
Houston Texans |
Indianapolis Colts |
1.635 |
0.836 |
12.1 |
Baltimore Ravens |
LA Chargers |
0.925 |
0.716 |
6.8 |
But to summarize, the formulas used here were found by logistic regressions and each element in the formula has a playoff significance of 95%. I promise if the more common offense metrics could say that, they would. I’ll also note that in vogue stats like FPI don’t really give answers markedly different from other common offensive metrics, such as Pythagorean expectation.
That said, offensive metrics like Pythagorean Expectation favor Seattle over Dallas by about half a point, or 52% win probability for Seattle. Offensive stats still favor Baltimore, but not as much. Simple Ranking stats favor Chicago by around 8 points, circa 75% WP. Houston-Indianapolis have approximately even offensive stats, so the difference between the teams is about 3 points. HFA is worth a bit more in the playoffs, circa 63%.