[greymule]

I don't recall any rule like that and at any rate would have a hard time imagining something that could qualify as a foul tip and be caught over fair territory. (OK, ball goes sharp and direct off the bat, hits the catcher's glove, rebounds into the air in front of home plate, and is caught by the catcher; or batter in front of box, F2 reaching out over the plate—yes, it's possible.)

However, ASA did offer a case play in which the batter bunted the ball in front of the plate and F2 dived forward and caught it in fair territory. The ruling was that the play qualified as an out, not a foul tip, since the catcher moved toward the ball. Thus some people studying the case book might have thought the criterion disqualifying a foul tip to be that the ball was caught over fair territory, when in fact it was that the ball did not go sharp and direct into the mitt or hand, but instead deflected such that "the catcher went to the ball."

So the fact that the ball was caught over fair territory was an unintentional red herring, since a ball deflected to the side such that F2 had to move to the ball and catch it over foul territory would also qualify as an out and not a foul tip.

Last summer, I did see a foul tip that was deflected at quite a large angle, though. The batter attempted to bunt a high pitch, and the ball deflected almost straight downward, sharp and direct into the catcher's mitt, with no perceptible change in speed or spin. Despite the severe change in angle, the defining criteria of "sharp and direct" were met, so it was a foul tip. (Why the catcher was holding her glove a foot off the ground when the pitch was 6 feet high is anybody's guess.)