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How Coaches and the NYT 4th Down Bot Compare

nytimes.com

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Re: How Coaches and the NYT 4th Down Bot Compare

#21

Post by altoz »

kosei wrote: post #10

Tough to take everything into account, but I find it troubling that all non-success/failure outcomes are not part of the calculation (ex: 8-yard gain on a 4th and 10; a fumble on a 4th and 2 run, etc). It simplifies the formula to the layman, but I have to imagine that it adds enough additional variance to matter, especailly considering we're talking in variances of less than half a point in their stated example. Als…

This is especially true of 4th down plays. A surprise play-action pass on 4th and 1 can go for an especially long gain and thus should have higher expected value. There's also the fake-punt scenario, which I suspect tends to be more successful than a regular 4th down.

Re: How Coaches and the NYT 4th Down Bot Compare

#22

Post by zeroonetwothree »

Uhhrrr wrote: post #2

Hm, so the data points for likelihood of getting another first down is based on data from the fourth downs that coaches actually attempted? It may be that the fourth downs they didn't attempt were not as propitious for some reason - wind (which the authors mention), injuries on key players, lateral positioning which doesn't favor one formation or another, etc.

No, it's based on third down data. The likelihood of converting 3rd and 1 is probably similar to that of converting 4th and 1.

Re: How Coaches and the NYT 4th Down Bot Compare

#23

Post by hkmurakami »

slg wrote: post #15
symbaton wrote: post #13

Earlier quoted context omitted.

People always say this, but it is actually true? Has any coach ever been fired for missing too many fourth downs?

I can't think of one off the top of my head. Mike Smith was under a lot of pressure a little while back for his aggressive decisions on 4th down (that were statistically correct IIRC) but wasn't actually fired. However, the obvious counter to your question is how many coaches really go for it frequently on fourth downs? Most coaches just follow the conventional wisdom unless they are already in a desperate situation…

So it sounds like fans and the media need to grasp EV first before coaches will be allowed to take the appropriate risks.

Re: How Coaches and the NYT 4th Down Bot Compare

#24

Post by swang »

altoz wrote: post #20
Zimahl wrote: post #6

Why would you ever go for it on 4th and 1 inside your own 10 yard line? You would put yourself at a severe disadvantage if you failed. Since the data from this is from previous plays in the last 10 or so seasons it is flawed. There probably isn't very little data of a team going for 4th and 1 and that deep in their own territory. The only time this has probably happened is in extraordinary circumstances - specificall…

I think statistically, if you punt from the 9 yard line, the other team is going to get excellent field position (around the 50 yard line). The difference between failing on 4th and 1 from your own 9 and the other team getting the ball around the 50 yard line is 41 yards of field position. That may sound like a lot, but I'd imagine the actual point difference is on the order of 2 points. The more interesting thing to…

No. Because you cost yourself 2 points and you give the ball to them. Essentially you gave them 2 points at the cost of being able to "punt" the ball at the 35.

Re: How Coaches and the NYT 4th Down Bot Compare

#25

Post by spinlock »

symbaton wrote: post #13
slg wrote: post #12

These type of articles never take into consideration the reason why coaches don't go for it as often as a computer might. The coaches face a reverse moral hazard when taking risks because the negative outcomes are multiplied for them. Even if the statistics support their decisions, a coach will be fired for taking too many risks and failing. Is gaining an extra 2% (or whatever) in expected returns worth the risk of l…

People always say this, but it is actually true? Has any coach ever been fired for missing too many fourth downs?

Ask Nick Saban how trying to kick a field goal with 1 second left in the Baylor game is working out for him. There are plenty of people saying that any other coach would be fired.

Re: How Coaches and the NYT 4th Down Bot Compare

#26

Post by aero142 »

spinlock wrote: post #25
symbaton wrote: post #13

Earlier quoted context omitted.

People always say this, but it is actually true? Has any coach ever been fired for missing too many fourth downs?

Ask Nick Saban how trying to kick a field goal with 1 second left in the Baylor game is working out for him. There are plenty of people saying that any other coach would be fired.

Nick Saban can call any number of schools right now and be the highest paid coach in NCAAF. He has a reputation for going for it on 4th down and taking risks. Also, it was Auburn, not Baylor.

Re: How Coaches and the NYT 4th Down Bot Compare

#27

Post by omegaham »

Zimahl wrote: post #11
thejteam wrote: post #8

Earlier quoted context omitted.

In place of 4th and 1 data AdvancedNFlStats would substitute 3rd and 1 stats. And I would agree that this substitution is suspect. Just a bit shy of bogus in fact.

Well, getting a yard in the NFL isn't typically a big problem and 3rd and 1 vs 4th and 1 are feasibly no different. But turning the ball over inside 30 yards is at least 3 points for the other team with only rare exceptions.

I think the biggest difference is that on 3rd and 1, the defense has already assumed that they're going to get a 1st down. The main job of the defense is to prevent a big gain and then get ready for stopping the offense on the next four downs. I wouldn't say that they're cheesedicking it, but they're not going all out.

Meanwhile, on fourth down, the defense is amped up and ready to roll. You'll usually see a strong blitz against a sputtering offense, and the percentage of plays that actually get a yard is going to be lower.

Not only that, going three-and-out means that the offense is unlikely to do any better going from the 10 to the 20 yard line. Better to punt the ball, trust your defense, and have your offensive coordinator fix whatever is going wrong.

Re: How Coaches and the NYT 4th Down Bot Compare

#28

Post by aero142 »

timfrietas wrote: post #5

This does not take into account an important factor that is somewhat intangible, but real to the psychology of the game: point swings. If you go for it on 4th and 1 at your own 1 and lose you are definitely down 3 points and probably 7. This puts pressure on your offense--which just failed on a 4th and 1--to somehow make it all the way down the field next time. That can be demoralizing for that offense, paralyzing in…

This actually seems measurable. Do teams that are behind perform worse on average? Do teams perform worse than normal after failing a 4th down attempt?

Re: How Coaches and the NYT 4th Down Bot Compare

#29

Post by twoodfin »

swang wrote: post #24
altoz wrote: post #20

Earlier quoted context omitted.

I think statistically, if you punt from the 9 yard line, the other team is going to get excellent field position (around the 50 yard line). The difference between failing on 4th and 1 from your own 9 and the other team getting the ball around the 50 yard line is 41 yards of field position. That may sound like a lot, but I'd imagine the actual point difference is on the order of 2 points. The more interesting thing to…

No. Because you cost yourself 2 points and you give the ball to them. Essentially you gave them 2 points at the cost of being able to "punt" the ball at the 35.

Ah, but sometimes two points is not so bad if the clock is a factor and you're about to turn over possession regardless. Down by one and facing a fourth down against the Broncos from his own one yard line with three minutes to go, Bill Belichick famously took an intentional safety[1]. The field position gain from the free kick was worth the two points, and the Patriots went on to win.

[1] http://sports.espn.go.com/espn/wire?id=1653659

Re: How Coaches and the NYT 4th Down Bot Compare

#30

Post by gerad »

slg wrote: post #12

These type of articles never take into consideration the reason why coaches don't go for it as often as a computer might. The coaches face a reverse moral hazard when taking risks because the negative outcomes are multiplied for them. Even if the statistics support their decisions, a coach will be fired for taking too many risks and failing. Is gaining an extra 2% (or whatever) in expected returns worth the risk of l…

I think there's selection bias in the underlying data. The dependent variable (realized success on attempted 4th down conversions) is conditioned on 4th down attempts by coaches.

Since coaches are conservative, they're likely to go for fourth down conversions only in cases when they are likely to succeed (due to defensive mismatches, etc).

Hence the model may over-estimate the benefit of going for it on fourth down.

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