Stolen Bases and PITCHf/x
I tend to think that pitchers have more control over the running game than catchers. Catchers control their "POP" times, while the pitcher controls his time to the plate, pickoff move, pitch location, and pitch type. The last two factors are probably the least significant in determining the success of a stolen base attempt, but they're the most quantifiable thanks to PITCHf/x.
Below is the success rate of stolen base attempts from 2008-2009 based on the pitch location.
The trendline is clear. The catcher has no chance at throwing out a baserunner on anything that's less than a foot off the ground. Balls at the belt and up give the catcher a 70% chance at throwing out the runner, and pitches (pitch outs) in either batter's box really level the playing field.
Looking at these charts, I don't see why there aren't more lefty-throwing catchers. SB success rates are even at 76% regardless of the batter handedness, so throwing through the batter doesn't pose much of a problem. In fact, a pitch has to be located a foot off the plate for the batter's handedness to have a 10% difference on SB%. And, again, most of that is just due to pitch outs being thrown in the opposing batter's box.
Speaking of pitch outs, base runners were safe only 45% of the time on pitches classified as 'PO' by Gameday stringers. And considering the 70-75% success rate on regular fastballs, a couple tenths of a run are gained by pitching out when the runner is on the move. However, the data I'm using show that runners were in fact running during only 15-20% of all pitch outs. Furthermore, The difference between a pitch out and a regular fastball in terms of pitch type linear weights is at least a tenth of a run. Therefore, as currently employed, pitch outs would have to nab runners about 90% of the time to break even. I've always believed that the pitch out (and hit-and-run) have been over-utilized tactics, and I'm waiting to see some data refute that.
Jorge Posada and Mike Napoli, who both struggle throwing out runners anyway, call for a very high rate of pitch outs. Backups Jeff Mathis and Jose Molina, who are far from defensively challenged, also call for their share of pitch outs, so those calls are likely coming from the bench. Humberto Quintero and the lethally armed Lou Marson never call for pitch outs.
There are several reasons to throw more fastballs with a man on first than with the bases empty; there's a chance for the double play, incentive to avoid the passed ball, and, of course, to control the running game. John Baker and Joe Mauer both caught about 60% fastballs with nobody on, but 70% with a man on first. Along that same line, here's a snippet of the leader board for pitchers who throw more fastballs with a man on than with the bases empty.
I don't know if it's Mauer and Baker, or if these organizations stress this strategy, or pure coincidence, but it's something. I included Mark Buehrle on the list because the man is, or he surely should be, legendary at fielding his position.
As for the other pitch types, base runners are successful 80-85% of the time running on off-speed pitches. Interestingly, on SB attempts of third, the lowest success rate has come on the knuckleball. Tim Wakefield must do a better job holding runners on second than he does on first. From the following, you can see that due to Wakefield, it appears that diminished velocity deters steals of third.
Combining velocity and location in a regression doesn't accomplish as much as I was hoping in terms of sorting out what catchers have had more or less difficult opportunities to gun down runners. Every catcher, save two, was expected to throw out 74-79% of base runners based on these factors alone. Only Wakefield's personal catchers Kevin Cash and George Kottaras have been forced to throw on especially difficult pitches. And they still have better numbers than Jason Varitek and Victor Martinez.