Tag Archives: Pro Football Reference

On April 28th, 2011, the Jacksonville Jaguars traded two draft picks–the 16th and 49th overall–to the Washington D.C. Football Team and moved up six spots in the first round to select quarterback Blaine Gabbert tenth overall. Using Kevin Meers’ (president of the Harvard Sports Analysis Collective) draft pick approximate value, did this look like a good trade at the time? No.

Meers’ chart, pictured below, uses the career approximate value statistic from Pro Football Reference going back through the last 20-plus drafts to estimate relative pick worth, and answer the question: what is a fair deal when trading draft picks for draft picks?


Using Meer’s valuation, you can see this never looked like a good deal for the Jaguars. On average the tenth overall pick is 39.9 (units1) more than the 16th pick, or 15 percent better. In giving up their second round, 49th overall pick worth 148.4, the Jaguars seemingly overpaid substantially. The difference between how much moving up was worth and what Jacksonville actually gave up–110 units–is worth the 82nd overall pick, in the middle of the third round. The trade would have been reasonable for a top-three pick; but, even just seven spots later down at tenth, the numbers indicate it was a bad idea.

The numbers do not tell everything. Meers’ valuation does not reveal that Gabbert was rushed into starting prematurely after presumed starting quarterback David Gerrard bizarrely left football, or that he played behind a below-average offensive line in each of his three seasons, including the third-worst league-wide his second year (per Pro Football Focus). These factors cannot be forgot. But after three years of awful play from Gabbert, yesterday the Jaguars traded him to the San Francisco 49ers, for the current fourth-to-last pick of the sixth round, worth about 45 points in Meers’ system.2 Ironic how that is the sort of pick the Jaguars should have traded to move up in the first place.

The good news for Jaguars fans is that it is over. Well, almost, as Gabbert will still count $1.807 million against Jacksonville’s salary cap this season in dead money. The good news for 49ers fans is that we have obtained a 24-year-old backup quarterback, whom our organization once thought highly of (and still somewhat does, apparently), for a very late draft pick unlikely to contribute to our current roster, and the well-documented quarterback whisperer Jim Harbaugh is still our head coach. (Yup, gotta’ save the best for last.)

  1. These particular numbers do not mean anything outside the chart; they are used to rank picks in a simple way. They are derived from real numbers, the career approximate value figures of Pro Football Reference. 
  2. The 49ers gave up the current fourth-to-last pick of the sixth round for Gabbert. That pick will not be 189th overall, as the league has a handful of compensatory selections to award between some of the rounds, but it should be close. 

In the 1980s, Dallas Cowboys head coach Jimmy Johnson sought to determine a baseline expected value for every pick in the NFL draft. This was a very good idea. Rather than just winging it each year when considering draft pick trades, expected values would provide the Cowboys front office a framework to build upon. Should Dallas trade the 20th and 80th overall picks for the 5th overall pick? How about the 50th pick for a first round pick next season? These questions require a sound process for good answers. Draft picks are precious commodities; aside from players, they are the currency teams use in deals with each other.

Coach Johnson’s system was not perfect. His extensive knowledge of football through years working in the NFL made the chart a good starting place.1 It contributed to the famous Herschel Walker trade (which has its own Wikipedia page), and helped set up the Cowboys three Super Bowls championships in the 1990s. But Coach Johnson’s preliminary valuation lacked a scientific process. Entire decades have gone by. There are oodles of data on players taken in the NFL draft, the length of their careers, salaries earned, touchdowns scored, tackles, expected points and win probability added, etc.

In the fall of 2011, Kevin Meers, of the Harvard Sports Analysis Collective, revalued NFL draft picks using the Career Approximate Value statistic compiled by Pro Football Reference. (Do read Mr. Meers’ actual article, which details the process.) This system is also presumably not 100 percent perfect, but it is a vast improvement, examining the career output of every single pick from 1980-2005.

How do the two systems compare? These are their respective charts:

Jimmy Johnson’s Draft Pick Value Chart, 1980s

Jimmy Johnson Draft Pick Value Chart

Kevin Meer’s Draft Pick Value Chart, 2011

Kevin Meers Draft Pick Value Chart

Notice first that Johnson’s system is more extreme, valuing the first overall pick at 3,000 and the 224th pick at three.2 Meers’ system values the first pick at 494.6 and the 224th at 39.8. Theoretically, the first pick is probably not worth 1,000 (!) last picks. Even if one of those picks is Tom Brady only one in one hundred times, 1,000 last picks would still yield ten Tom Bradys (Tom Bradies?) while just one first overall pick could yield a maximum of one Tom Brady. Of course, that sentence illustrates that theory is sometimes ridiculous! What would a team do with 1,000 late round draft picks, even over a period of several years? Only 53 people can make the team. Nonetheless, Johnson’s system appears to overvalue the first overall pick by at least a factor of ten, if not a hundred.

The key problem with Johnson’s chart is that it overvalues earlier picks and undervalues later picks. Earlier picks are still better! (Duh.) Meers’ chart, a product of data, still indicates that with each additional pick, the likely career output of the drafted player declines. And Meers’ chart still finds that the rate of decline is decreasing: the drop in expected value from the first to the second pick is many, many times larger than the drop from the 223rd pick to the 224th. The theory and logic behind each chart is the same. Meers’ simply uses actual data, which reflects a different, more accurate picture.

As I wrote yesterday, the San Francsico 49ers are in excellent shape for the upcoming 2014 NFL Draft. Meers’ chart is a big reason why. The 49ers will likely have SIX picks among the first 100 in the draft this spring. That the 49ers first pick comes 30th overall is not a reason to get down in the slightest. The antiquated valuation undervalues such picks: the 100th pick is worth only one-three-hundredth of the first pick in Johnson’s system. But, actual data indicates the 100th pick is more likely worth one-fifth of the first. The 49ers should have six picks with fairly high expected values. And with an already talented roster, they may trade to move up and get a player even more likely to succeed, without giving up all their picks in later rounds.

Remember, draft picks are free money in the NFL; teams get them every year just by being in the league. With the most picks in this draft, the 49ers are rich. Big spending is not just a thing for free agency.

  1. Similar to Dick Vermeil’s Two Point Conversion Chart, which I wrote about here. 
  2. The first overall pick is worth 3,000…what? Dollars? No, just units. The charts have been scaled to simple numerical values, as their purpose is for relatively ranking the picks within them. 

Earlier today while cleaning up my Favorited Tweets on Twitter, I came across one I’ve been meaning to look into for a while. It was a “TwitPic” of a simple chart, conceived at UCLA in the early 1970s. This is it:

Vermeil 2 Pt Chart

Credited to Dick Vermeil, an assistant coach at the time, versions of the chart have been around longer, but for whatever reason, this is “The One” that still hangs around college and NFL sidelines, albeit perhaps with a few minor changes unique to each coach. It’s fairly evident that, while getting on the right track, there are some serious problems with the chart, which Vermeil himself has long acknowledged (Battista).

Generally, the chart says to go for two when you can make the lead (either yours or your opponent’s) a small multiple of three (FG) or a multiple of seven, also valuing the 17 point lead and the 10 point deficit. Interestingly, the chart suggests going for two when down by one and by nine, something I certainly can’t recall a lot of coaches doing these days. Since 2006, only three times have offenses attempted a two point conversion when down by one, and only once when down by nine. NFL coaches don’t treat the chart like an ironclad law. Have they changed it for the maximum strategic advantage? Not quite.

Coaches still seem a little hazy about how the game clock affects two point attempts. The chart has nothing to say about the amount of time left in the game, but certainly it’s a factor. If it’s the first quarter, even if you can tie the game, why risk it? There are many possessions left for each team. But with under a minute in the 4th quarter, every coach would go for two to tie the game. When does it become necessary? Depends who you ask. In a 2002 Miami-FSU game with 11:44 left in the fourth quarter, FSU kicked the extra point to take a 13 point lead. Miami subsequently scored two touchdowns, holding FSU scoreless to win the game. FSU coach Bobby Bowden said afterward:

I don’t go for two early. If we missed it, a touchdown and two field goals would beat you. (Hutton)

Apparently, 48+ minutes into a game can still be “early”, and Bowden, head coach of a major NCAA Division I football program, was concerned about Miami scoring on three possessions, even though it would only take two to beat FSU. Herman Edwards, former head coach of the New York Jets and Kansas City Chiefs, liked to wait until 12 minutes remained in the game before considering a two point try (Battista). In 2011, then analyst Michael Lombardi (now general manager of the Cleveland Browns) expressed his own thoughts:

Continue to add points. Do it until the amount of possessions remaining is dwindling. The discussion to go for two should never occur until the fourth quarter, when possessions are limited. (Lombardi)

It turns out that even before the 4th quarter, going for two can still be the strategic play. Harold Sackrowitz, a statistics professor at Rutgers University, is as expert as anyone on two point conversions, having spent years studying them and tinkering with probability models. He accounts for potential future possessions, the time left, the score, and even the probability of converting given the strengths and weaknesses of the offense and defense. And with all of that in mind, he knows teams should start considering to go for it in the middle of the third quarter (Battista).

How have two pointers fared recently? Using Pro Football Reference’s Play Finder, one can see that of the last 500 two point conversions attempted in the regular season (as many as they’ll show at once, going back to November 2004), 49.2% (246) succeeded while 50.8% (254) failed. Of the 31 attempts so far in 2013, 45.2% (14) have succeeded while 54.8% have failed. Actually I was a little discouraged by those numbers. 500 is a pretty fair sample, and with a 49.2% success rate, I suspect it yields the same number of expected points as an extra point (due to its much higher, still not 100% success rate). Are teams just going for two in the wrong situation or the wrong time, or are they going for two in the wrong situation, or the wrong time, and still not going for it enough? Mr. Sackrowitz thinks yes, and that teams should go for it more. Vermeil, now retired after a renowned coaching career, agrees:

I don’t think it’s a situation you can perfect. I do say this: I believe it’s probably you don’t go for two points often enough. Now that I sit and watch on TV and don’t have that pressure, I can say, “You guys are chicken.” (Battista)

As time goes on, it will be interesting to see if they are proven right.

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