For offenses to be most effective, they need to be unpredictable. In the 2nd and 10 situation, this means defenses would have to prepare for the nearly equal chance of a run or pass. Many analysts refer to ‘balance’ as the key to unpredictability. But balance itself doesn’t matter if the offense is predictable in achieving its balance. Running and passing on every other down would provide perfect balance but would be completely predictable. That’s why randomness is at least as important as balance to keeping the defense on its heels. Anything other than random play selection provides a pattern, however subtle, that an opponent can detect and exploit….

Coaches and coordinators are apparently not immune to the small sample fallacy. In addition to the inability to simulate true randomness, I think this helps explain the tendency to alternate. I also think this why the tendency is so easy to spot on the 2nd and 10 situation. It’s the situation that nearly always follows a failure. The impulse to try the alternative, even knowing that a single recent bad outcome is not necessarily representative of overall performance, is very strong.

– Brian Burke, Advanced NFL Stats.

It turns out most teams are predictable on 2nd and 10, if not quite as predictable as the Jets have been in the first few games of this season. If you’re interested in play-calling tendencies at all, click-through and read the piece (and look at the graphs); it’s good.

Also, a fun fact: Brian Burke is the first cousin of my former roommate Ted Burke.

Hat tip to reader Brian (not Burke) for passing this along.