On the fourth play of the Jets’ opening drive against the Chargers on Sunday, after a 1-yard run on first down left Gang Green in a 2nd and 9 situation, someone — presumably offensive coordinator Brian Schottenheimer — called for a pass.

This is notable because, as Mike Salfino pointed out last week, the Jets have passed the ball every single time they’ve faced a 2nd and 9 in the first quarter this season.

The Chargers sent linebacker Takeo Spikes charging just outside the Jets’ left tackle, where he was met by Jets fullback John Conner. Conner put a good first hit on Spikes but failed to hold his block, and Spikes slid off in pursuit of Mark Sanchez.

Sanchez, under pressure, threw the ball slightly behind tight end Dustin Keller cutting across the right flat. Keller had a step on linebacker Donald Butler but had to slow to juggle the pass. He corralled it briefly, but by that time Butler and linebacker Shaun Phillips had converged on the ball. Butler stripped it from Keller during the tackle and returned it 37 yards for a Chargers touchdown.

Here’s why it’s so hard to point fingers in football games, to oversimplify the way we like and identify some single bugaboo as the problem on any team or drive or play.

None of Schottenheimer, Conner, Sanchez or Keller made a mistake so egregious to deserve all of the blame for the play. But if Schottenheimer had called something less predictable, if Conner had done a better job keeping Spikes at bay, if Sanchez had made a better throw or if Keller had held on to the ball, the outcome of the play would have certainly changed.

And all that said, it still took an excellent play by Butler (and a decent one by Spikes) to earn the touchdown.

Luckily, Sanchez made some better throws later in the game and Keller did a better job holding on to the ball. The play-calling appeared to improve, too, but then that’s the type of thing that generally operates on a positive-feedback loop: It’s always easier to call the next play when the last one worked.

The Jets won, which matters most. Plaxico Burress caught three touchdown passes. He deserves a fair share of the credit, but he likely wouldn’t be enjoying any if the Jets’ offensive line didn’t do a great job protecting Sanchez and opening holes for Shonn Greene, and if Greene, in turn, hadn’t done a fine job steamrolling defenders in the open field.

More to follow.