Great post by Bruce Jenkins (seriously).
Make sure to read the whole thing to hear the rest of Kruk's take, but here's a snippet:
When Raul Ibanez tripled off reliever Jeremy Affeldt in the seventh inning last night, scoring Chase Utley from second base for a 6-2 lead, Mike Krukow told his audience that "Posey tipped that pitch." You don't hear such things from other analysts, particularly the shameless "homers" befouling so many broadcast booths, but Krukow is a former catcher who plays it straight, and he can't stand to watch shoddy fundamentals.
"What happened there," Krukow said this morning in Philadelphia, "it was a 3-2 count, and Posey shook his head as Affeldt looked in for the sign. When a catcher does that, he's not shaking off a pitch. He just wants to have the pitcher shake HIS head -- like he's going to get inside the hitter's head. Well, 99 times out of 100, a fastball is coming. We (in the booth) figured Utley relayed the pitch to Ibanez. He'd been late on Affeldt's fastball the whole at-bat, but he jumped all over that one."