tag:blogger.com,1999:blog-38600807.post3087248538484104570..comments2023-09-09T10:36:20.114-04:00Comments on Advanced Football Analytics (formerly Advanced NFL Stats): Sterling Moore and Split-Play WPAUnknownnoreply@blogger.comBlogger18125tag:blogger.com,1999:blog-38600807.post-59530909742405304742012-03-19T17:36:52.222-04:002012-03-19T17:36:52.222-04:00i think this is stupid because you cant drop a cat...i think this is stupid because you cant drop a catch like that with couple seconds to go there is no reason to drop that ball. The defender did what he had to do which is break that play up.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-44641343741375299762012-01-26T18:46:15.832-05:002012-01-26T18:46:15.832-05:00Dan S makes a good point. The WP calculator puts o...Dan S makes a good point. The WP calculator puts out smoothed empirical averages. In very tight final-minute situations, it is imprecise.<br /><br />Often, when I'll do a specific analysis, I'll go back to the data and built a customized look at the situation to include timeouts and other factors. But not everyone has that luxury and it takes a lot of time.<br /><br />Other types of models may be superior at this point in such a game. It's one reason why I'm a fan of Keith's drive Markov model. For example, in many cases where the 2 models produce contradictions we can learn where teams are making sub-optimum choices.Brian Burkehttps://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-65978686638811967432012-01-26T17:25:36.918-05:002012-01-26T17:25:36.918-05:00I think it's been well established in the past...I think it's been well established in the past that WP values are not at all precise, particularly in the end-game situations that we're most interested in. And I don't mean that in an intuitive, "no way is that the actual prob" way. The calculator can clearly be shown to be directly contradictory of itself.<br /><br />Rather than try to smooth out the sparse and incomplete play-by-play data, it's probably better to write an algorithm that can calculate probabilities at the point where it because reasonable to predict the number of plays left in the game.<br /><br />In any case, I love this site but cringe any time I see a final drive WPA analysis like this one.Dan Snoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-46316905798213173622012-01-26T15:12:53.319-05:002012-01-26T15:12:53.319-05:00The EP aren't adjusted for time. With :27 seco...The EP aren't adjusted for time. With :27 seconds left on the 14, the Ravens are given a +4.74 EPA, with a 83% chance of a FD and a 45% chance of a TD. If I change that to 3 seconds left, the EP doesn't change, even though no coach in the league would (or should) go for a TD at that point.<br /><br />For WP to be accurate in end-of-game situations, it needs to take into account the clock as a factor. The Ravens didn't have a 45% chance of scoring a TD from the 14 with that little time left, because the number of plays they could run in 27 seconds with one time out (and needing to kick a FG if they didn't get the TD) was just as much a constraint as the downs were.<br /><br />EDIT: deleted some comments with typos.Dave Archibaldhttps://www.blogger.com/profile/05939754767057460853noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-91015131060468482242012-01-26T15:04:12.274-05:002012-01-26T15:04:12.274-05:00I have seen some oddities with WPA in other situat...I have seen some oddities with WPA in other situations. For instance, in New England's game against Denver in the Divisional round, New England had the ball on first down. They threw an incomplete pass, and their WPA went up, +0.08 . Brian, I have an open question about it on its "live" page if you want to check it out. Also, I thought I'd point out that the game logs that drive the graphs often have missing plays, almost always when the time-remaining is the same as a previous play. (I only notice this because I've absolutely loved poring through the data this season - thanks again for providing such a cool way of looking at everything!)<br /><br />By the way, I've seen a few other examples of split-play that could more clearly be identified. One clear example would be when a play gets called back due to penalty. Denver@Buffalo, week 16 - Eddie Royal returns a kickoff for a touchdown, nullified by penalty. The penalty was worth negative WPA, but not a lot. However, figuring in the positive WPA of the lost touchdown, it was a huge play. Although I'm not sure if you allocate WPA to players for penalties.tunesmithnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-41877820690792115192012-01-26T15:01:55.922-05:002012-01-26T15:01:55.922-05:00This comment has been removed by the author.Dave Archibaldhttps://www.blogger.com/profile/05939754767057460853noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-80681327122649329532012-01-26T14:56:41.364-05:002012-01-26T14:56:41.364-05:00There's something screwy with the Win Probabil...There's something screwy with the Win Probability Calculator. It says that 3rd and 1 has a WP of 83%, while first and 10 from the same spot has a WP of 63%. I don't see how having a first down lowers your WP at all, much less so drastically. Even 1st and goal from the 8 only has a WP of 70%.<br /><br />Parameters: Score differential of -3, time left 0:22, 4th quarter, Field Position is opponent's 14, 3rd down and 1 to get WP of 83%.<br /><br />Changed field position to 13, down to 1 and "To Go" to 10, get WP of 63%.Jameshttps://www.blogger.com/profile/01838293735141324662noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-3522518904737700102012-01-26T13:54:33.206-05:002012-01-26T13:54:33.206-05:00Ah, crap, you're right.Ah, crap, you're right.Independent Georgehttps://www.blogger.com/profile/14559237565237736636noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-44223657822296597162012-01-26T13:33:37.068-05:002012-01-26T13:33:37.068-05:00Independent George - FG & TD are mutually excl...Independent George - FG & TD are mutually exclusive outcomes so P(FG) + P(TD) must be less than 1.<br /><br />In your example P(FG) + P(TD)= 1.305.<br /><br />In my example I assumed 5% chance of no score, which means 95% chance of score, so I assumed P(FG) + P(TD) = 0.95. If you assume TD gives 100% WP, FG gives 50% WP, and no score gives 0% WP, then you have<br />0.83 = 100%*P(TD)+50%*P(FG)+0%*P(no score).<br /><br />I forget what this is called in linear algebra but it has a unique solution.Jared Doomhttps://www.blogger.com/profile/17445479616742729527noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-17508380613111688342012-01-26T13:21:52.722-05:002012-01-26T13:21:52.722-05:00I'm not sure even with the further breakdown t...I'm not sure even with the further breakdown this intuitively makes sense. Moore's (first) play is significant because without it the Patriots lose - going from 90% probability of losing to essentially 100% is a more important play than going from 50% to 60% at some other point in the game.<br /><br />There's almost a compounding effect here: without Moore's 2nd-down play, the 3rd-down pass breakup and the FG miss (both more important in terms of WP) can't happen. Then again, without those two events, his pass breakup is just a footnote. So maybe WP is "right" and it just feels inaccurate because I have the benefit of hindsight.Dave Archibaldhttps://www.blogger.com/profile/05939754767057460853noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-60461381283085514662012-01-26T13:18:23.750-05:002012-01-26T13:18:23.750-05:00Should say AFC, not NFC, in the firs sentence.Should say AFC, not NFC, in the firs sentence.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-72057572156833568212012-01-26T13:02:39.604-05:002012-01-26T13:02:39.604-05:00I might be misunderstanding the math, but I came u...I might be misunderstanding the math, but I came up with about a 35% chance of a touchdown.<br /><br />Assuming a TD is ~100% WP, and a FG is ~100% overtime, the WP is the probability of a TD + probability of a FG + OT win<br /><br />0.83 = P(TD) + P(FG)*0.5<br /><br />If P(FG) = 0.95, then<br /><br />0.83 = P(TD) + 0.95*0.5<br />0.83 = P(TD) + 0.475<br /><br />0.355 = P(TD)Independent Georgehttps://www.blogger.com/profile/14559237565237736636noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-89964263420274004652012-01-26T12:43:05.175-05:002012-01-26T12:43:05.175-05:00Wo doesnt Know how many timeouts a Team has. It ju...Wo doesnt Know how many timeouts a Team has. It just considers how many Teams historically habe scored a Td, or Made a FG in that Situation. Teams typically pass in this Situation and that means 22 Sec correspond to about 4 plays. Even Ehen you waste a play in getting the 1st thats enough chances for scoringKulkohttps://www.blogger.com/profile/17657346387956365135noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-24626207054492714162012-01-26T12:23:45.784-05:002012-01-26T12:23:45.784-05:00Anon #3 - To be fair I did say *eventual* TD, so I...Anon #3 - To be fair I did say *eventual* TD, so I was accounting for a TD on any following play, and still thought 83% was high, given the limited number of plays you can run with 22 seconds left.<br /><br />I think the WP model implicitly (kind of) accounts for timeouts because I think it is based on historical data (albeit probably smoothed for situations with sparse data points).Jared Doomhttps://www.blogger.com/profile/17445479616742729527noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-84020508679005433872012-01-26T12:04:46.715-05:002012-01-26T12:04:46.715-05:00In the 2011 regular season, FGs of 1-29 yards were...In the 2011 regular season, FGs of 1-29 yards were missed 11 times; total is 301 for 312, or 96% if I counted right. (I didn't count XPs, but there were 6 missed). So that's a good SWAG.<br /><br />Where the 83% comes from is that in addition to scoring the immediate third down touchdown, they could get a first down instead and run a couple more plays before kicking the FG. I don't believe the WP generator takes TOs into effect, and I can't remember if BAL had one left or not.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-49261597164025680552012-01-26T11:54:02.006-05:002012-01-26T11:54:02.006-05:00I was also surprised with that, Jarod. I won't...I was also surprised with that, Jarod. I won't use your math (because I don't know it), but the probability of Baltimore kicking a FG at that point should have over 75%. Then it's overtime on the road against a superior team (per EPA).<br /><br />How that translates into the Ravens having a 83% WP, I don't know.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-7279680112487645352012-01-26T09:54:41.933-05:002012-01-26T09:54:41.933-05:00Flacco screwed up that play. He clearly had enoug...Flacco screwed up that play. He clearly had enough room to run it and dive for the first down. Lots of room! Ugh.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-16719588405412734392012-01-26T09:12:49.910-05:002012-01-26T09:12:49.910-05:00"Third and 1 from the NE 14, 22 seconds remai..."Third and 1 from the NE 14, 22 seconds remain: 83% win probability."<br /><br />That seems high. I'm assuming eventual TD leads to GWP ~ 1.0, eventual FG leads to GWP ~ 0.5, and failure to score leads to GWP ~ 0.<br /><br />Assuming the probability of FG OR TD is 0.95, that implies the probability of an eventual TD is 0.71 [(0.71 * 1.0 + (0.95 - 0.71) * 0.5 + (1.0 - 0.95) * 0) = 0.83].<br /><br />Given only 22 seconds left a 71% chance of scoring an eventual TD on 3rd & 1 from the opponent's 14 seems high. Am I wrong (assuming yes, but still surprised)?Jared Doomhttps://www.blogger.com/profile/17445479616742729527noreply@blogger.com