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This is the sort of broken thinking that prevents NFL coaches from trying this. The numbers just don't agree with your premise. Brian Burke of Advanced NFL Sta

• slg 13y ago
  Except those numbers are optimized for winning while head coaches have other motivations, most importantly keeping their job. While there will be a lot of overlap in the two (e.g. winning means not being fired) a coach introduces a lot more risk of losing their job the further they deviate from the common wisdom. So even if the expected points suggest going for it, it might still be in the coaches best interest to kick. It is basically the opposite of moral hazard.
  • charlieflowers 13y ago
    If the numbers truly support it, then NFL coaches, of all people, should adopt it. They are supposed to have balls and care more than anything about winning. If the facts truly support it, I expect we will soon see NFL coaches adopt it.
    • macspoofing 13y ago
      You're right, but again, nobody ever got fired by buying IBM.
    • cylinder 13y ago
      An NFL coach will never risk his job by trying something so bold and untested. If he tried it for just one game, and it failed, he could lose his job. New, creative schemes always come up from minor leagues like high school and college before gaining general acceptance in the pros. The only way it happens is if the directive or permission comes down from the owner[1]: "I will allow you to never punt for two seasons or until we have an adequate sample size to judge this method." [1] Thinking about all the fun things I could do with billions of dollars, like buy an NFL team and run experiments like this, make me question the sanity of people who turn down $3 billion to continue working on their photo sharing app.
      • aaronbrethorst 13y ago
        Which begs the question: what does Mark Cuban allow of his coaches that no other NBA owner would?
• 001sky 13y ago
  You only go for it if you have better than average odds of getting it. Its not like random draws from a known distribution. Any included data on 4th down is going to be subject to some variation of survivorship bias. See, for example, also the consideration: I used only data from the 1st and 3rd quarters to exclude situations hurried by an expiring clock and by desperate teams or teams with large leads playing differently late in games. So, by this logic the 4th down data is similarly non-standard, no? It would clearly be a situation different than normal 1-3 downs in 1-3 quarters.
  • tghw 13y ago
    4th down data is not non-standard for 4th down data. Sure, you can't say for sure what would have happened if they had gone for it, but there's nothing particularly different about these downs that would lead to a higher conversion rate.
    • thejteam 13y ago
      I think the point is that if you are using game data then the only times the offense is currently going for it on fourth down is because they have some reason to believe they can make it with a high percentage. Football is not played with random number generators, the coaches and players understand the matchups and the chances they have of making X yards with the players and plays they have available. The teams that didn't go for it might have a reason to believe that with the players on the field the probability of them getting X yards was small.
• corresation 13y ago
  He even has a calculator so you can now add incorrect statistical decision making His methodology is suspect. The entire premise (there have been similar reductionist statistical studies that holistically look at it as pure positional numbers) is founded on the notion of the weighted point value of each 1st down position. But as others have mentioned, on-fire offenses against miserable-defenses (e.g. New Orleans taking on Dallas) are going to absolutely dominate such a ranking, because they're of course going to dominate first downs (the survivorship bias -- the ones who suck go three and out), and they're more likely to be scoring points, completely throwing off such a weighting. If you're dominating a game but have a couple of missed passes, coaches often will go for fourth downs. If you're having little success, on the other hand, why give up good field position, and instead try to just push them back and hold them off until you can regroup. If Minnesota is 3rd and 4 at their own 35, they quite rightly -- and with full statistical backing -- aren't going to go for it if it isn't a desperate last minute drive. We of course have actual stats on the probability of making a fourth down- http://espn.go.com/nfl/statistics/team/_/stat/downs/sort/fourthDownConvPct http://espn.go.com/nfl/statistics/team/_/stat/downs/sort/fou... And the probability of blocking such an attempt- http://espn.go.com/nfl/statistics/team/_/stat/downs/sort/fourthDownConvPct/position/defense http://espn.go.com/nfl/statistics/team/_/stat/downs/sort/fou... Teams have a less than 50% chance of making it on average, though of course specific teams and specific opponents will completely throw off that count, and such is what weighs on the minds of coaches making these decisions, having to do so outside of "if we were an entirely average team against an entirely average team..."
  • tghw 13y ago
    Teams have a less than 50% chance of making it on average Ultimately, that's not what matters. Expected value is what matters. Take the example from the video of a team on its own 5 yard line with 7 yards to go: If they go for it and don't make it, they leave the other team with the ball on the 5 yard line, which they will convert into a touchdown 92% of the time, an expected value of -6.44 points. If they punt, the TD conversion goes down to 77%, an expected value of -5.39 points. Therefore, the break even is about 16% 4th down conversion rate. If a team can make it more than 1 in 6 times, they should go for it instead of punting. Since most NFL teams are in the 40-50% range, they should be going for it more often.
• dwd 13y ago
  The problem with numbers is you have none until someone tries something different. The Chargers took a chance with Aussie Darren Bennett and the drop punt "Aussie kick" is now in everyone's playbook. It's probably worth someone recruiting an ex-Union fly-half and see what tricks he can teach a quarter-back.
  • lancewiggs 13y ago
    There is so much more that could be done in American Football, within the rules, that Rugby Union takes for granted. Onside passing is one.
    • JackFr 13y ago
      I think more has been tried than you imagine, look at the single-wing offenses of the 1930's and triple options offenses. But ultimately, the stop-and-go nature of American football makes possession so important that there isn't much to be gained by all the laterals.
• cylinder 13y ago
  Similarly, in basketball, the pick and roll is pretty much a flaw in the game. Teams should just pick and roll every single time, but they don't, because coaches get bored too.
  • sebkomianos 13y ago
    Where do you base this on?
• ubernostrum 13y ago
  This is the sort of broken thinking that prevents NFL coaches from trying this. AFAIK the main reason NFL coaches don't try stuff that's too unusual is that although it makes a good trick a time or two, this is... well, professional football. Defenses will adjust. Right now I'd suspect a lot of the success of going for it on 4th down, or going for two-point conversions, comes from the fact that opposing defenses aren't expecting it. But the minute you become known as "the coach who always goes for it", well, they're going to defend it (and in fact they'll have an easier time defending it since they know you're not going to try anything else).
  • selectodude 13y ago
    So they would approach is like they already do for downs 1 through 3? It's not a trick, it's using all four downs to your advantage, vs wasting a down giving the ball away.
    • ubernostrum 13y ago
      It's not a trick It is an unusual deviation from the normal sequence of play-calling, and the advantage is that much of the time opposing defenses aren't prepared for it. They have plays set up for when they need to make a stop -- particularly at the goal line -- but they're not used to using them in this situation and it is, I suspect, almost entirely the novelty of being forced to run the "must stop this one play" defense that makes it a successful tactic. Which in turn implies that if people start doing it all the time, defenses will simply adjust, become accustomed to making a dozen or so fourth-down stops per game, and that will be the end of this "Opposing Defensive Coordinators HATE him -- learn this one weird trick" story.
• JackFr 13y ago
  Burke's piece is excellent, in as a far as it goes -- however, expected value is not the only thing one should concern themselves with. Higher moments matter. In particular, in a given situation, when ahead a coach might choose to trade negative expected value for a reduced in variance, and when trailing do trade negative expected value for increased variance. (It looks like his calculator may account for this in some way through win probabilities, but I didn't see an explanation on the site.)
  • twoodfin 13y ago
    He mentions at the end of the piece that his EP-based analysis only applies in "typical" close games in normal weather when the clock is not yet a major factor. And that an analysis based on Win Probability could correct for most of these factors. I'm skeptical of that last point. There are many, many variables that underlie football outcomes. Unlike baseball, where the most critical two players by far in any situation (the pitcher and the batter) are known in advance by both teams, a football play has the potential to be affected dramatically by any combination of players on the field. I am sympathetic to the idea that more teams should play aggressively on offense more often (and indeed I believe there are signs of this in today's NFL), but by no means should every team be expected to act according to the punt/FG/go-for-it chart in most situations. I think you're absolutely right to emphasize variance tradeoffs. When coaches try to reduce variance they are often criticized as "risk-averse", but that's often a winning strategy, even in games that are close enough score-wise to be considered "typical".