PatsFanSince74

You have to read Carroll's book, The Hidden Game of Football (see my posts above). That's exactly what he tries (!) to do, i.e., take into account down and distance, field position and time of game. His problem, as I said elsewhere in this thread, is that his output is one number, representing the most likely outcome but without indicating the standard deviation or any other measure of the inherent volatility around the prediction.

And yes, you're completely right; the expected value of a passing play is higher than a running play, but the volatility around that value can be quite significant depending on the circumstances. So, saying that the most likely outcome of a pass over the middle to Wes Welker is a gain of 12.5 yards (making that up) and the most likely outcome of a pass down the field to Randy Moss is 22.7 yards doesn't take into account the standard deviations around both of those numbers. In other words, the "outputs" of 12.5 and 22.7 are simply one number along two curves that could have very different distributions.

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Synovia

The success rate on "unexpected" onside kicks is over 50%. The problem is that most of them happen during those down by 4 with 35 seconds left situations, where the defense is trying to defend one.

patchick

Yep, I don't even think that automated decision making like that is even part of the goal for the foreseeable future. Rather than creating a perfect computer model, the goal as a coach is to use the data to adjust your own mental model to counteract the irrationalities that come from conventional wisdom...and from being human. IMO, it's pretty clear that Belichick is very active in pursuing this. After watching the Pats so much, I find myself astonished watching other teams punt on 4th and 1 from the opponent's 45.

As a draftnik, I'm particularly interesting in how they number-crunch draft strategy, like the example of taking advantage of the 1-round bump for delayed picks. It seems to me that while the Pats are very aggressive with risk on the field, they take a much more risk-averse approach to the draft -- e.g. trading down from the 1st round so often.

(BTW, for those who get tired of hearing about draftee measurables, this is what that's about for me. It's just a way to collect data to try to find tendencies that predict selections and success. E.g., the fact that the 2 drafted WRs with the lowest shuttle times since 2002 are also the only 2 WRs who have made an impact with the Patriots as rookies is interesting, no?)

patchick

The one you called "densely and poorly written"? OK, I'll try...

Synovia

Expected points compensates for opponent field position. IE, if you turn the ball over at the 20, you go from 5 expected points, to your opponent having 2 expected points.Loss of 7 expected points (numbers made up, but concept is correct)

Synovia

I don't think the trading down actually is risk-adverse. I think they difference between a low 1st rounder and high 2nd, isn't the potential, but the chance they hit it. IE, they're amassing higher variance players who happen to cost much less. Its the same sort of thing the red sox did with smoltz and penny (which didn't work out): you've got a pretty full roster, so guys with high potential (even if they have low chance of hitting it) are much more valuable than guys who should be decent players but won't be good ones.


Plus, they're taking advantage of a serious market inefficiency when they're trading this year's 2nd for next year's 1st.

SunnyDenmark

another point about morale.

I am no 'westpoint' graduate - but morale often times is grossly overlooked in the history of battles (in favor of equipment, tactics, manpower advantage, terrain, etc). It is almost like morale is an afterthought. But it is very important. A demorilized enemy can be a very ineffective fighting force.

How does this relate to NFL? In regards to 4th down conversions - it was stated how about the affect on morale after the attempt? If 4th down is NOT converted by your teams offense: sure you are demorilized BUT the most directly involved (offense) gets to go off the field and 'regroup'. Your teams defense - whom are your 'reinforcements' -are fresh and motivated. However, if the 4th down conversion is sucessfull for your offense, the other teams defense is demorilized AND they also have to stay on the field to continue fighting for at least another 3 downs. So lets say even if it was a 50% / 50% proposition (at say the 50 yard line) - the morale 'penalty' is more severe on the other team. That in itself is an advantage even if the attempt is successfull only half the time.

patchick

Right -- except as I read it, in this study they only considered the opponent's expected points when the drive ended in a turnover. Field position after a punt, missed FG or failed 4th-down conversion wasn't a factor.

PatsFanSince74

Great comments.

For the NFL, this science is still in its infancy.

As you rightly observed in an earlier post, it's a very different matter in MLB where you have the limits of innings and a ginormous database on just about every aspect of the game and the tendencies of every player, including a strike zone divided into 16 blocks or something. There are enough data, for example, on what Batter A has done with a 2--2 count with runners on second and third with two outs in the bottom of the ninth on a calm, clear day with temperatures in the mid 70's at home against L and R handed pitchers and enough data on what Pitcher B has done against Batter A or in similar situations to make predictions more meaningful. Baseball has the benefit of a much more clearly defined set of data and situations that has been gathered now for decades. As large as the ultimate database is, it is well within the capacity of today's more powerful home or office computers, without having to turn to a mainframe. Don't get me wrong, this isn't "simple" to model; it's just that the variables have been clearly defined and tracked for a long time.

For the NFL, the data are much "softer" and, in the past, have been regarded as almost unanalyzable. 22 different players have a direct impact on the outcome of every play; is the Safety likely to blitz? How does our Back do on picking up that blitz? How has our line done against their nose tackle in the past? So far today? etc., etc. Down and distance, field position, game situation, current score, each team's risk profile for the game (is it a "must win?"), how each of those 22 individual players is likely to perform, field conditions, weather. All of these variables interact with each other to present a much more complex decision model.

The computing capacity required to turn what used to be regarded as "soft" and/or "unanalyzable" data into information in real time is probably beyond what most NFL teams have on board today. Our home PC's could probably clunk out an answer after twenty or thirty minutes; a mainframe could probably do it in a couple of minutes, but there are 40 seconds between plays, with at least 20 of them needed to get the players on the field and up to the line.

I have a nifty monte-carlo program that runs all sorts of fun simulations for me, but I have time to fix my lunch and bring it back to my desk in the time it needs to do 100,000 even simple calculations. What we're talking about here is a model with hundreds, if not thousands of variables that need to be run against each other many thousands of times in order to come out with an expected outcome and the shape of the distribution around that outcome...and then boil the whole thing down to a set of simple outputs that the HC can digest in five seconds and make a decision that accounts for the risks involved and his own "gut."

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makewayhomer

almost every 4th down study says the same thing: coaches SHOULD be going for it a lot more than they should. coaches aren't aggressive enough

and there is a reason for this: coaches are so afraid to lose their jobs that they stick to conventional wisdom, b/c that won't get them fired. going for it on 4th and inches from your own 30, though, might well get a coach fired if it doesn't work.

or any other example from the Buffalo/Jets game the other week. tie game, Buffalo driving with less than a minute to go. they advance far enough for a 50ish yard FG attempt, and then what do they do? they stop trying to advance more and kill the clock!!!

they settled for a coin flip FG instead of actually trying to advance more. move the ball another 10-15 yards and your win % skyrockets. but they didn't want to take that "chance" I guess b/c they were afraid of 1 horrible outcome (TO). so, so , so dumb. but this way, when the kicker misses the FG, it's his fault, and not the coaches!!!

not getting fired has become more important than doing the smart thing