Reader LCee asked earlier this week: "Jack, several years ago, Joe Sheehan made the comment to the effect of: a fast runner on the bases might distract the pitcher and certain infield position players, but that pales in comparison to the impact on the hitter, as he must protect the runner with lame swings when the runner attempts a steal. What is your take?"
It's an interesting question and one that deserves some consideration. I believe that the article LCee is quoting from is this Baseball Prospectus piece from 2004, which includes this passage: The vaunted secondary effects of stealing bases--distracting the pitcher, putting pressure on the defense--do not appear to exist. In fact, most secondary effects argue in favor of keeping the runner on first base. A runner on first is more disruptive to a defense, with the first baseman holding and the second baseman cheating towards second for a double play, than a runner on second. Additionally, studies show that stolen-base attempts negatively impact the performance of the batter at the plate, presumably due to hitters getting themselves into negative counts by taking pitches or swinging at bad balls to protect the runner.
The article doesn't include links to any studies that show negligible secondary effects of base-stealing or the supposed negative impact that a runner attempting a steal has on the batter. Sheehan has numbers on his side, so if I see the studies he's referencing it will surely be harder to support my perspective. From a common-sense standpoint, however, it's difficult to believe that an altered pitching motion and a limited pitch selection does not favor the batter.
A pitcher generally changes his pitching motion when holding a runner on base, by throwing from the stretch to decrease the amount of time it takes to deliver the ball to the catcher. Pitch selection changes as well; a pitcher simply cannot throw as many breaking balls to a batter with Jose Reyes on first base, because if Reyes tries to steal on a breaking pitch he's going to be standing safely on second.
The arguments about defensive positioning make sense, and I agree that the batter - especially if he's left-handed - benefits more from a big hole between first and second base then from simply having the runner on second. Still, any run expectancy matrix shows that a team is more likely to score with a runner on second than with a runner on first, given the same amount of outs. Given that, I simply cannot agree with Sheehan's first contention.
One other point: no study can possibly measure the psychological effects that a fast runner on first has on the pitcher, and I have to believe that most hurlers are simply less comfortable with a runner on base then pitching with the bases empty. I know I'm veering dangerously close to "intangibles" territory here by trying to predict psychological influences, but I do think the logic behind my thinking is strong. Again, if I saw some of the studies that Sheehan referenced, I may think differently.
However, I do not need to see any studies to be convinced of Sheehan's second contention. All the advantages that I believe the batter has with a fast runner on first are immediately given away the second that the runner actually takes off. The best possible scenario is that the pitcher throws a ball that is clearly out of the strike zone and the batter recognizes this and checks his swing, allowing the baserunner to steal safely. Otherwise, the batter finds himself taking a strike in an attempt to let the runner steal, or takes a defensive hack to protect the runner and to avoid the double play.
Forget about the hole that appears when the shortstop or the second baseman goes to cover on the steal attempt; a hitter trying to hit the ball through that hole is indeed taking a compromised swing and therefore less likely to hit safely. In my opinion, the best thing the batter can do is simply step back and let the runner earn his base, without trying to help out.