Game Probabilities - Week 17

Weekly game probabilities are available now at the nytimes.com Fifth Down. This week I also discuss home field advantage when a dome team visits a cold climate.

The 2009 All-WPA Team

The day after the Pro Bowl rosters are announced there are the obligatory "snub" articles in local papers around the country. In the DC area, the annual London Fletcher snub article is simply reprinted from last year's Post. So what about those Vincent Jacksons and Cedric Bensons who were unfairly left off the roster in favor of big name stars who may not have had a particularly good year? Who really earned their ticket to Miami?

I'll compare players using two different stats. Win Probability Added (WPA) measures each play's increase or decrease in a team's chances of winning. For every play that a player is mentioned in the play-by-play description, including penalties, turnovers and everything else, the WPA is tallied in his name. WPA is a narrative stat. It tells the story of what happened and is very context-dependent. It measures performance when it matters most. It has limited applications in terms of predicting future player performance, but it my mind it's perfect for comparing Pro Bowl and MVP contenders--even Hall of Fame candidates once there's enough data.

Request: Who Are The Pro Bowl Snubs?

I'm working on a comparison of players who were either selected for or snubbed from the Pro Bowl rosters. I'm tabulating each player's Win Probability Added (WPA) and Expected Points Added (EPA). In the comments here, list the players you think were legitimate all-pros but weren't picked. "Fantasy" positions only please (QB, RB, WR, TE). Except in rare cases, I can only analyze the positions that get run with, catch, or throw the ball.

Thanks!

Andy Reid Is No Longer My Hero

Note: This post was taken from a series of comments on the recent Games of Week post. Thanks to all who contributed to the discussion.

About a month ago Eagles head coach Andy Reid was my hero of the week for his daring, and smart, onside kick to open the game against the Redskins. Although it failed and gave up 7 points, he got them back by going for it on 4th down inside field goal range, succeeding, and getting the touchdown.

This past week, however, Reid is again the goat. With 3 minutes left in a tie game against the Broncos, the Eagles faced a 4th and 1 from their own 49. The Eagles punted. This was a big mistake, and you don't even need fancy math or some win probability model to prove it. Worse, Reid made the exact same call a year ago in the infamous tie against the Bengals.

If you have a 4th and 1 at about the 50 and you go for it, the value of the two possible outcomes are exactly equal. In other words, either I have a 1st down at the 50, or my opponent has a 1st down at the 50. It's perfectly symmetrical. Now consider what punting means.

Team Playoff Probabilities - Week 17

Courtesy of NFL-Forecast.com, here are the latest playoff forecasts.

The NFC teams are locked up. Only the seeds are left to be settled. The AFC wildcard contenders keep losing. Only the Jets and Ravens control their own destinies this Sunday.

Run-Pass Imbalance on 2nd and 3rd Downs

I've recently been looking at the imbalance in the payoffs for running and passing on first downs. The results suggested that most teams should generally pass more often outside the red zone and run more often inside the 10-yard line. What about 2nd and 3rd downs?

Game theory tells us that when the payoffs for two strategy options are unequal, the strategy option with the higher payoff should be selected more often. As the opponent adjusts to counter the new mix of strategies, the payoff of the favored option will decline while the unfavored option becomes more lucrative. Eventually, the payoffs for both options equalize, and at this point the overall payoffs are optimum. In two-player zero-sum games this is known as the minimax, or more generally as the Nash Equilibrium.

I used Expected Points (EP) to value the payoff of each play. Expected Points measures the net point advantage that the play result gives to an offense. It captures the value of yardage gained and lost, first downs, sacks, penalties, turnovers, and everything else in terms of equivalent point value. The change in EP resulting from a play is called Expected Points Added (EPA).

One of the things EP does not measure is the time value of a play. In situations when a team has a significant lead, the true value of a run includes the time burned off the clock. To a team behind late in a game, pass attempts have more value because they are more likely to stop the clock. For this reason I only include plays in the first and third quarters and when the score is within 10 points. This excludes trash-time plays and plays affected by the clock.

Team Efficiency Rankings - Week 17

It looks like the Bengals really are frauds, as Rodney Harrison kindly called them last Sunday night. Well, maybe not frauds, but they are an average team posing as a dominant division winner. Anything can happen in a single elimination tournament like the NFL playoffs, but I wouldn't count on them going very far.

It's no surprise the Jaguars have fallen apart down the stretch. They have been a slightly below-average team for most of the year.

The reigning champion Steelers are still a very good team, but are a long-shot for the playoffs. Had Roethlisberger been able to play in the the first game against Baltimore, which was lost in overtime, the wildcard situation might be very different right now. That was a division and conference game, which would come in very handy in a tie-breaker.

The Jets had a relatively small chance to make the playoffs through most of the season despite their 3-0 start. That all changed in the 3rd quarter against the Colts. On the first series without Manning and their other starters, the Colts gave up a sack, a fumble, a touchdown, the lead, and a perfect record. They also handed the Jets a very strong hand going into the final week. Colts fans are upset at losing the shot at perfection, but maybe the fans who should be most upset are those of the Broncos, Steelers, Jaguars, Texans, and Dolphins.

Games of the Week

Tonight's game notwithstanding, the game of the week was the Denver-Philadelphia game. What started to look like a blowout turned into a barnburner. Down big early, the Broncos came back to tie before surrendering a late field goal. DEN 27 PHI 30 (EI 4.9).

The runner up was the Baltimore-Pittsburgh game (4.0 EI). The Ravens were down by 10 at the half but came back to tie in the 3rd quarter. They had multiple opportunities to win the game, but imploded with penalties. BAL 20 PIT 23.

The comeback of the week was also the upset of the week. New Orleans gave up a commanding lead over Tampa Bay, and ultimately lost in overtime. TB 20 NO 17. At their low-point in the game the Buccaneers had a 3% chance of winning (CBF 33).