[greymule]

That is only true if appealed while B5 is at bat. If appealed after B5 completes the at bat, but before the first pitch to B6, B4 IS declared out and removed from base, the result of B5's at bat is nullified (excepting any outs on the play) and B5 is brought back to bat (unless B5 was put out on the play, in which case B6 comes to bat).

I suspect you'll change your mind when you think again about this play.

Once they throw a pitch to the next batter, whether that batter is the proper batter or not, the previous batter, whoever it was, became legal. That was B3 in this case. Now that B3's at bat is legal and B4 is on base, the proper batter is B5, no matter who is standing in the box at the time. Since B5 is indeed the proper batter, when he completes his time at bat, he has simply completed a legal time at bat. There's nothing to appeal. The defense's claim that B4 failed to bat in the proper order is false.

Now if the defense appealed before a pitch to B5, that's of course a different story. Then B4 is out, B3 is taken off 3B, and B5 bats.