(Updated: reader Jeffrey Lang-Weir pointed out that there is a definition in 2, which led to this re-write)
Rule 2 defines interference.
(a) Offensive interference is an act by the team at bat which interferes with, obstructs, impedes, hinders or confuses any fielder attempting to make a play. If the umpire declares the batter, batter- runner, or a runner out for interference, all other runners shall return to the last base that was in the judgment of the umpire, legally touched at the time of the interference, unless otherwise provided by these rules.
Rule 7.08 deals with when a runner’s out, and this is what those who would argue that A-Rod should have been called out are referring to:
Any runner is out when –
(b) He intentionally interferes with a thrown ball; or hinders a fielder
attempting to make a play on a batted ball;
Rule 7.08(b) Comment: A runner who is adjudged to have hindered a fielder who is attempting to make a play on a batted ball is out whether it was intentional or not.
Now, watching the replay it’s pretty clear that when he runs through, that’s okay: as long as he doesn’t get in the way of the fielder making the play, he’s fine.
The issue is – does yelling at the fielders count as hindering them as they attempt to make a play on the batter?
While what we see enforced in games is is that physically hampering the fielder is illegal (and almost never done) while vocally attempting the same thing is, at least, not enforced, it’s clear from the definition that confusing the fielder is illegal and offensive interference.
As long as it’s not enforced – like foreign substances on uniforms for pitchers – a runner would be dumb not to take advantage of it when it could so clearly help his team.
With two outs, too, what’s the harm? If it doesn’t work, inning over. If it works, huge benefit. There’s no reason for him not to try, and that’s why it’s a smart play on his part. I’m sure – to editorialize for a second – that if this had been Jeter, or if you don’t think Jeter would do that, pick a saavy popular veteran of your choice – that this would hardly be the subject of that much controversy.