## Wildcard Game Probabilities

Arizona started 7-3 then lost 4 of their last 6 games to finish 9-7. Baltimore started the season 2-3, then reeled off 8 wins in their last 11 games to finish 11-5. The Colts were 3-3 before their 9-1 run to finish 12-4. Philadelphia's post-season hopes were dim at 5-5-1 before winning 4 of their last 5 games to sneak into the playoffs. Miami was 2-4 at one point this year. San Diego was 4-8.

A lot of what we see with these turnarounds and winning streaks can be explained by opponent strength and random bunching of wins and losses, but not all of it. Teams can fundamentally improve and decline, most often due to injuries. There are many other factors too.

Matt Ryan and Joe Flacco are not the same players they were the 2nd week of September. The Wildcat offense isn't the novelty it was in week 1. And Peyton Manning's knee is no longer the swelling ball of fluid it was in September. So for my playoff probabilities this year, I'm going to base all the calculations on the most recent 8 games for each team.

I'll also provide the probabilities based on the full regular season stats for comparison.

 Pwin GAME Pwin 0.74 ATL at ARI 0.26 0.43 IND at SD 0.57 0.52 BAL at MIA 0.48 0.62 PHI at MIN 0.38

Full-season stats produce the following probabilities: ATL over ARI 0.63 to 0.37. SD over IND by 0.65 to 0.35. MIA edges BAL 0.56 to 0.44. And PHI over MIN by 0.67 to 0.33.

Edit: Probabilities based on stats excluding week 17 games are in the comments below.

### 6 Responses to “Wildcard Game Probabilities”

1. Brian says:

I wonder, however, if only counting the last eight games could have an opposite effect as well. Indianapolis rested starters the final week. I'm not sure what exactly Arizona was doing the final three weeks.

Next week, when you do the divisional round, 3 of the 4 bye week teams rested starters in week 17. So while eliminating the first 8 games gives us a good idea of a how a team is playing right now, it is also increasing the effect of these "meaningless" late season games for some teams.

2. Brian Burke says:

That's a good point. I had thought of doing that but was in a pinch for time yesterday.

Here are the probs based on games 9-15 (excluding week 17):

ATL over ARI by 0.80 to 0.20
SD edges IND 0.59 to 0.41
MIA over BAL 0.61 to 0.39
PHI over MIN 0.58 to 0.42

It looks like the Ravens are only team to be affected significantly by excluding week 17. And their week 17 game was a hard-fought meaningful one, at least for them. I watched it and it looked like the Jaguars were playing to win. Fred Taylor was out, but everyone else played the full game. They even led the game briefly.

My read is that the BAL-MIA game is a toss up. Miami is a solid above average team across the board. Baltimore relies on big plays to win, both on offense and defense. The Ravens have an insanely high defensive interception rate, which I don't factor into the predictions. If that continues, they'll have a big advantage.

3. James T. says:

Have you ever studied "momentum", or are you familiar with any other study on the subject? Conventional wisdom seems to be that the Colts and Ravens are favourites because they've "looked so good lately", and the Colts have won something like nine straight games, and it's all coming together at the right time, etc.

My instinct is that momentum doesn't exist, or at least the effect is so small as to be nearly indetectable, and that all this Colts talk is just the usual retrospective justification and ill-informed prattling. I read a study in Baseball Between the Numbers that suggested that teams that finished strong were actually worse off in the playoffs, since they were likely winning by riding their best players, leaving those players worn out for the post-season. But football is much more a team sport than baseball, of course, so maybe there is something more than good luck at play when a team reels off a number of wins in a row.

4. James T. says:

Whoops:

I misspelt "momentum" when I first tried to search for it in your archives, sorry. But it might still be interesting for someone to investigate whether finishing strong provides any advantage in the playoffs.