Tuesday, January 13, 2009

Is 3rd and 6 a running down in the NFL?

by jjbtnw

This post probably has more to do with an interesting query result than suggesting an alternative strategy for coaches. I was taking a peek at the 2005 play-by-play data that is available on this site (thanks Brian!). I had just separated everything into drives and series. I was wondering what the most efficient pass/run mix was, historically. One of the funny looking query results that I turned up was the following matrix of down-and-distance and conversion percentages. This data is limited to the 2005 data and does not include first downs gained by penalty. Nor does it exclude garbage-time drives or time-pressure drives. It does include playoff games and goal-to-go series.

Down Distance Pass Conv% Run Conv%
3 1 63.5 76.3
3 2 50.8 60.8
3 3 50.8 57.9
3 4 46.9 53.6
3 5 43.1 47.4
3 6 43.2 55.2
3 7 38.7 36.8
3 8 33.9 26.6
3 9 31.1 32.9
3 10 32.2 27.6

To me it is interesting to see that running is a better strategy on
3rd down for distances of 6 yards and less. One of the reasons that running is so effective is that it is apparently unexpected. The next table shows the same down-and-distance situations, and how many of each type of play occurred in the league.

Down Distance Pass Plays Run Plays
3 1 203 548
3 2 364 260
3 3 423 133
3 4 467 110
3 5 531 95
3 6 526 67
3 7 507 76
3 8 501 64
3 9 396 76
3 10 603 87

On 3rd down and 3, 76% of teams pass instead of run. And thepercentage of passing on 3rd down with more yards than 3 needed for a first down only gets higher. So most defenses on 3rd and 3 or higher will be implementing a pass-oriented scheme and personnel package. And 3 out of 4 times (or even more often) they will be making the correct call. Given those circumstances a run play would be expected to be more successful. And apparently, it is. According to game theory, if coaches were calling the correct run/pass mix, the conversion percentages would be nearly identical. For 3rd and 6 or less, they aren't. So the obvious assumption is that more running plays should be called on 3rd and 6 than are currently being called in the NFL. Of course, this post would need to be backed up by data from more than one year to validate any assumptions made.


Jason said...

I think that's fascinating. Even on higher yards-to-go downs (look at 3rd and 9!), running isn't that much worse a strategy than passing.

The mindset, of course, is different. If a team with a third and 10 runs a draw play and doesn't get the first, the fans boo because the offense is "giving up." If they throw an incompletion on third and 10, nobody gets overly upset about it.

jjbtnw said...

Yeah, these numbers really surprised me when I saw them. What they show is how effective a run can be when a pass is expected. But your observation about why a coach or coordinator would call a pass when a run is a statistically better choice is spot on. They'll get lambasted by the press and the announcers for calling a run, but not a pass.

ingdo said...

Isn't 1st down conversion rate just part of the equation? The run conversion percentages on 3rd and 9 might be greater than the corresponding pass conversions,but the latter,on average go about 6 yards further downfield.

That enhanced field position is probably enough to make the passing option more valuable in terms of putting points on the scoreboard.

The 55,2% run conversion on 3rd and 6 looks likely to be either a small sample size blip due to random chance or an error in the pbp data.

missthebeachnow said...

Great call on the unexpectedness of it. Yes, 3rd and long seems to favor the run, but if teams took that info and ran more than they passed in those situations, I doubt those percentages would continue to hold true. By my count, 86 percent of 3rd and 6 plays are converted by passing. If that cruised closer to 50/50, I think teams would have to start to play the run more.

Also I am wondering how many of those are actual handoffs, vs. drop backs where the QB finds a seam to run? I wonder what RB's conversion rates are vs. QB's running on 3rd and long. The QB has the option to choose to run only if he believes he can get the first down yardage. The RB is locked in to running only. If the coast is clear even Brady will run for the easy one. But he isn't going to take off with a linebacker between him and the marker. When the call is a handoff, if the QB doesn't audible, the RB doesn't have a choice. He has to run it.

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