Why are lefty catchers so rare?

Of the 30 current major-league starting catchers, not one of them throws left-handed. In fact there are several, like the Tigers’ Robert Fick and the Blue Jays’ Darrin Fletcher, that bat lefty but throw righty. No Hall-of-Fame backstop was a lefty thrower either, but Yogi BerraMickey Cochrane, and Bill Dickey all batted from the left side. The reason is base stealers. When there is a runner on second, as opposed to first, the pitcher is hard-pressed to pick them off. It is mostly up to the catcher to nail the runner at third should he attempt to steal. This is made a bit tougher by the fact that most hitters are right-handed, and stand in the batter’s box directly between the catcher and third base. But as long as the catcher is a righty, he can jump forward and have a clear line to throw. Were he a lefty, he would have to jump backwards, taking all of his momentum out of the throw — his ability to cut down runners at third would be severely hindered. So in the minors, coaches teach young lefty catchers to throw right-handed.