tag:blogger.com,1999:blog-38600807.post9045604860781983491..comments2023-11-05T04:16:44.937-05:00Comments on Advanced Football Analytics (formerly Advanced NFL Stats): C.J. Spiller and the Effect of Increased CarriesUnknownnoreply@blogger.comBlogger23125tag:blogger.com,1999:blog-38600807.post-4828807214715947482012-12-22T11:09:52.854-05:002012-12-22T11:09:52.854-05:00Here's the deal with AD's lower EPA. Becau...Here's the deal with AD's lower EPA. Because Ponder sucks, the Vikings run in situations where for the average team, the optimal option is to mostly pass. Therefore AP's 2nd and 12 runs are being compared to most teams 2nd and 12 passes and as good as Peterson is, he isn't as good as a competent passing game in a lot of the situations he's being used in. Ergo we see a -EPA. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-42305675064907091532012-12-19T12:55:20.524-05:002012-12-19T12:55:20.524-05:00How many "great" backs in the past 30-40...How many "great" backs in the past 30-40 years played on perennially good teams? Just thinking off top of my head a very short list. Most of the ones that come to mind were on bad teamsHowardhttps://www.blogger.com/profile/14501972171844533607noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-17746548692142170692012-12-18T03:59:21.125-05:002012-12-18T03:59:21.125-05:00"I simply pointed out that RBs, according to ..."I simply pointed out that RBs, according to the EP/play, hurt their team. They result in negative pointed expected. Thus the conclusion would be to never run the ball (which is obviously ridiculous)."<br /><br />since no one else has addressed this, i will try. in any given down and distance, a team has a baseline expected points scored. the e.p. of a play is zero when that number doesn't change. suppose, for instance, that if a team has a first and goal on the fifty, they will, on average, score 4.2 points. if they throw an incomplete pass, that will be negative e.p. if they gain 5 yards, that may or may not gain them e.p., depending on the situation (if there was 1 second on the clock, anything that isn't a score has negative ep). in each situation, there is a breakeven point where the expected points remain the same. running plays, on average, do not reach that threshold. <br /><br />the fact that runs have negative ep does not in any way show that teams should never run. it simply shows that they should run less. if runs were less frequent, defenses would defend against them less, and therefore the e.p. would go up. at the same time, the value of passes would decrease. eventually, an equilibrium would be reached where the e.p of passing and running is equal...in fact, this equilibrium would be reached when the e.p. of passing and running both equal zero (neither would have an effect on how many points the team is expected to score).<br /><br />as others have mentioned, there are also reasons to run EVEN if it is known to have negative e.p. (because WP is really what matters), but even if that weren't the case, negative e.p. on average for runs would not suggest that the rb position should be eliminated.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-25868053992331594342012-12-16T22:43:49.314-05:002012-12-16T22:43:49.314-05:00Wade-Interesting theory, but no. The overall negat...Wade-Interesting theory, but no. The overall negative average EPA and WPA values for RBs and runs in general have existed consistently through the years in the data set in addition to the current year.Brian Burkehttps://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-42300311210674250002012-12-16T22:41:19.468-05:002012-12-16T22:41:19.468-05:00This post was by Jack, not Brian. This post was by Jack, not Brian. Brian Burkehttps://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-44996341330349190462012-12-16T13:58:36.940-05:002012-12-16T13:58:36.940-05:00anon, re: RBs having more endurance. Good points...anon, re: RBs having more endurance. Good points by you and Brian.<br /><br />Perhaps that is why the NFL has largely gone to a tandem RB strategy. I'd point out though that DLs do rotate frequently as well, but still you do see those huge guys wear down. It does seem that RBs would have an endurance advantage.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-20129650410666729672012-12-16T12:38:50.647-05:002012-12-16T12:38:50.647-05:00Brian in the article you allude to RBs having more...Brian in the article you allude to RBs having more endurance and possibly being more effective late in the game as the defensive line wears down. I have long wondered if this bit of conventional wisdom holds true and would suggest it for a future study and article. Or if it exists if anyone could point me to it. Intuitively Ive always questioned why the defensive line gets more tired than the offensive line. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-44976562467915225852012-12-16T11:25:54.913-05:002012-12-16T11:25:54.913-05:00OnSolThree, and Anonymous
thanks for your commen...OnSolThree, and Anonymous<br /><br />thanks for your comments, but they do not relate to this discussion. I simply pointed out that RBs, according to the EP/play, hurt their team. They result in negative pointed expected. Thus the conclusion would be to never run the ball (which is obviously ridiculous).<br /><br /><br />No one ever mentioned quarterbacks. I agree with both of you, quarterbacks are important.<br /><br /><br /><br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-46269762437534672802012-12-15T19:10:26.142-05:002012-12-15T19:10:26.142-05:00The 16th best average QB this year is worth 1.7WPA...The 16th best average QB this year is worth 1.7WPA while the 16th best RB is worth 0.26WPA. <br /><br />Compared to the 16th best QB the top QB is relatively worth 4.48-1.7= +2.7WPA over 16th best<br /> <br />where the top RB is worth 1.52-0.26= 1.26 WPA over 16th best<br /><br />The top QB is still worth more but the gap tightens Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-20341723991157044822012-12-15T18:00:36.072-05:002012-12-15T18:00:36.072-05:00>Obviously, EP/P is not representative of the v...>Obviously, EP/P is not representative of the value of a RB, because it states that the NFL should eliminate the position. It simply does not capture all the important elements, it simply looks at down and field position (and time - please clarify this if I am incorrect). <br /><br />You are correct. However, WPA basically looks at "in-context" EPA. If you look at that this year, the highest rated running back so far is at 1.52 WPA, while the highest rated QB is at 4.48. Quarterbacks are simply more important.<br /><br />>And this notion of 'what RB lead a team to a SB' is ridiculous.<br /><br />Exactly. You need a competitive passing game to succeed. You do not necessarily need *any* other facet of the game as much. OnSolThreehttps://www.blogger.com/profile/11911865362711339523noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-36545276297752541002012-12-15T17:29:45.950-05:002012-12-15T17:29:45.950-05:00My final point. If you look at it from a win proba...My final point. If you look at it from a win probability added over average player at that position per play, then RB's don't look basically pointless as they do from a raw EPA/P perspective. In fact Ray Rice and maybe Peterson if you just looked at his pure rushing looks more valuable than any of the top QB's with enough attempts using this method. If you use the replacement player method then But I agree with Brian that they RB's are overpaid and overvalued in general. <br /><br />A great QB is just intrinsically more valuable because having a QB's skills seem more repeatable and transferrable to other teams. RB's just can't take so many poundings without it affecting their skills in a material way. Most RB's don't stay great for very long. It's also harder for them to do well behind a bad OL. <br /><br />Also the offense tends to run through the QB. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-16033995196310511112012-12-15T16:53:35.254-05:002012-12-15T16:53:35.254-05:00There are a couple other biases that exists betwee...There are a couple other biases that exists between RB's.<br /><br />1. If they don't play every down there is a bias if they are used in situations that lead to more EP on average.<br /><br />2. I haven't done a full study but it certainly looks like RB's average more yards per carry on carries when their team is trailing vs when they are ahead. I'm not sure if this works out as far as WPA and EPA. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-91561027575332347962012-12-15T16:38:02.237-05:002012-12-15T16:38:02.237-05:00RB's look more valuable/useful whatever word y...RB's look more valuable/useful whatever word you want to use if you compare them to the average at their position in Win Probability added which is probably a more useful metric to compare them to QB's with. When coaches want to run a safe time killing play they are calling some plow up the middle that might have negative EP value on average but slightly above average WPA since it is killing clock.<br /><br />Also its important to compare players on the site to their average or replacement level counterpart. Offense and more so passing has definitely shifted upward all around.<br /><br />Also Adrian Peterson doesn't look as good on EPA/play here because his receiving value is dragging him way down. He's either a really bad receiver compared to SPiller or he is getting too many dumpoff passes when no one is open that have little to non chance of succeeding. <br /><br />I'd say Terrell Davis, Marshall Faulk, and the three headead monster of Jacobs, Bradshaw Ward were pretty vital to their teams winning but they also had at least great QB's<br /><br />The top end QB's are worth quite a bit more than the top RB's but it doesn't make the top RB's worthless either. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-88991600841013491062012-12-15T13:11:36.961-05:002012-12-15T13:11:36.961-05:00Brian,
Couldn't a negative EP for RB overall b...Brian,<br />Couldn't a negative EP for RB overall be a result of the parameters from the model being estimated from historical data which may not accurately reflect the the "expected" part of the game today? Maybe defenses are better now, or running backs are not quite as good as they were? <br /><br />Do you think it is a *possible* explanation for the negative EP?Wadehttps://www.blogger.com/profile/01886400484337256831noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-85250167571658128352012-12-15T12:03:12.345-05:002012-12-15T12:03:12.345-05:00adding one point, RBs have -0.2 EP/P and teams ru...adding one point, RBs have -0.2 EP/P and teams run about 25 times a game. that is -5 points per game. Quite a significant point spread, and if fact slightly greater than the average point spread in nfl games in the 2012 season.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-43698469968031942232012-12-15T11:50:40.865-05:002012-12-15T11:50:40.865-05:00OnSolThree, teams run the ball around 25 or 26 ti...OnSolThree, teams run the ball around 25 or 26 times a game.<br /><br />Obviously, all these plays are not detrimental to the team. <br /><br />Obviously, EP/P is not representative of the value of a RB, because it states that the NFL should eliminate the position. It simply does not capture all the important elements, it simply looks at down and field position (and time - please clarify this if I am incorrect). <br /><br />And this notion of 'what RB lead a team to a SB' is ridiculous. What LB led his team to the SB. What Center? What DT? What cornerback? What safety? What OT? etc. <br /><br />If the point is that a qb is more valuable than an RB, that is obvious. But that is not the point, the point is that RBs have a negative EP/P and thus "should" never touch the ball, which is nonsense.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-90177782198774256832012-12-15T03:02:10.573-05:002012-12-15T03:02:10.573-05:00He said which *great* RB, not which running back. ...He said which *great* RB, not which running back. Here's a list of the past ten Super Bowl champions' starting RBs:<br /><br />Ahmad Bradshaw<br />James Starks<br />Pierre Thomas/Reggie Bush<br />Willie Parker<br />Ahmad Bradshaw/Brandon Jacobs<br />Dominic Rhodes/Joseph Addai<br />Willie Parker/Jerome Bettis<br />Corey Dillon<br />Antowain Smith/Kevin Faulk<br />Michael Pittman<br /><br />I think the only one you could even argue was great was Jerome Bettis. On the other hand, look at the QBs:<br /><br />Eli Manning<br />Aaron Rodgers<br />Drew Brees<br />Ben Roethlisberger<br />Eli Manning<br />Peyton Manning<br />Ben Roethlisberger<br />Tom Brady<br />Tom Brady<br />Brad Johnson<br /><br />A few all-time greats there, and whatever you think about Eli Manning, he's at least good. OnSolThreehttps://www.blogger.com/profile/11911865362711339523noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-17741359824067426742012-12-14T23:24:24.570-05:002012-12-14T23:24:24.570-05:00"It seems that EP is not representative of an..."It seems that EP is not representative of an RB's value, since the league average EP/P is below zero."<br /><br />Or, it means the league improperly uses and values its RBs. <br /><br />"Tell me, which great RB most recently led its team to a championship?"<br /><br />--------------------------<br /><br /><br />um, all of them had a running back, and they were used on about half of all offensive plays.<br /><br />keep in mind, we are not talking about "leading them to a SB", we are talking about "having a negative effect per play". that is what the negative EP/P means.<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-43069234678225801902012-12-14T21:24:49.564-05:002012-12-14T21:24:49.564-05:00"It seems that EP is not representative of an..."It seems that EP is not representative of an RB's value, since the league average EP/P is below zero."<br /><br />Or, it means the league improperly uses and values its RBs. <br /><br />Tell me, which great RB most recently led its team to a championship?Brian Burkehttps://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-44434426407846202572012-12-14T18:45:19.222-05:002012-12-14T18:45:19.222-05:00Well passes are included in a RB's EP which do...Well passes are included in a RB's EP which doesn't help take things into finer detail. It would be helpful if running EP and receiving EP for a RB'were separate collumnsAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-9083549865062295642012-12-14T18:30:58.433-05:002012-12-14T18:30:58.433-05:00I agree with Alan, it seems pretty obvious that t...I agree with Alan, it seems pretty obvious that the entire NFL would take Adrian Peterson over CJ Spiller.<br /><br />It seems that EP is not representative of an RB's value, since the league average EP/P is below zero. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-11349667962800135522012-12-14T15:06:28.373-05:002012-12-14T15:06:28.373-05:00Great stuff as always. I was actually just wonderi...Great stuff as always. I was actually just wondering about this last weekend as the announcers were talking about how Peterson was one of those backs who "gets stronger as the game goes on" without any actual evidence. However, I'm not sure your analysis fully addresses that question. You are averaging the EPA for an entire game, correct? Would a truer test be to look at the EPA of each carry independently and see if it increases or decreases as the volume goes up (e.g. compare EPA of carry 1 to carry 20)?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-13728022444762220282012-12-14T09:41:48.779-05:002012-12-14T09:41:48.779-05:00I'm a Vikings fan and have a hard time not goi...I'm a Vikings fan and have a hard time not going with AP as the league's best back. But I do like this analysis as I've been saying to people for some time that Spiller is a very very talented and underrated back. I mean, the guy might break Jim Brown's record!<br /><br />The Bills sure have drafted a lot of good RBs the past few years (Spiller, Marshawn Lynch, Willis McGahee).SlackerInchttps://www.blogger.com/profile/08275358994906136088noreply@blogger.com