4 every THOUSAND chances. A couple more per season, no? Who gives a crap? Posada was hitting a huge number of HR's.
But the difference then becomes that if a pitcher cannot trust his catcher to block a pitch in the dirt, he's less likely to throw it down and thereby leading to leaving his pitches up, thereby leading to more mistakes high in the strikezone, thereby leading to more extra-base hits, thereby leading to more runs scored against him, etc., etc., etc.
Ask pitchers in Texas, Detroit and New York what they felt about throwing to Ivan Rodriguez.