via graphics.boston.com

The most remarkable development in the 2008 Red Sox season has been speed. Coming off of last year, we expected great pitching, and we expected solid offense. But how many of us were expecting the Sox in June to be second in the league in steals?

Jacoby Ellsbury is almost single-handedly responsible for this achievement. He has 34 stolen bases, leading the majors in that category. Since getting caught for the first time in his major league career in May (after 25 steals), he has only been caught three more times, giving him a phenomenal success rate of 89%. Ellsbury has already shattered the Sox rookie record for steals (31), and is well on his way to breaking the Sox team record of 54 steals, held by Tommy Harper. Ells is on pace to rack up 73 stolen bases.

After Ellsbury, the biggest culprits are Coco Crisp (12 SB, 2 CS) and Julio Lugo (9 SB, 3 CS), followed by Dustin Pedroia (7SB, 0 CS). Pedroia's numbers surprise me, considering that 1) he is not a fast base-runner and 2) he never had this sort of success in the minors. He already has as many SB as he accumulated in all of last year.

Overall, the Sox have 70 thefts this season, and their baserunners have only been caught 13 times. Their success rate is 84%, better than the Rays (75%) and the Angels (72%), who are respectively first and third in stolen bases. If the Sox continue to steal at their present rate, they will swipe 151 bases this season.

Exciting as steals are, they often are overrated. Because of the intrinsic danger in giving up outs, most Sabermetricians argue that you need to steal bases with a success rate of 75% or higher for it to be worthwhile. (This article discusses that figure, and other interesting SB stuff.) Moreover, more steals doesn't necessarily equal more runs. The 2005 Red Sox scored 910 runs, but only stole 45 bases; by contrast, last year's team scored 867 runs, with 96 steals. And our current team projects to score only 822 runs,  while stealing 151 bases.

As Ellsbury's prowess for base-stealing becomes known through the league, it could become harder for him to steal. Tuesday's game stands out in this regard. Ellsbury was on first with two outs, and swiped second despite a pitch-out. He then broke for third, and the catcher's throw nailed him, ending the inning. With his speed, Ells could have scored from 2nd on just about anything, so stealing third was an unnecessary risk.

So what do you think about the blatant thievery going on? Will Ellsbury keep up his record-setting pace? Is Pedroia's success sustainable, or will his aggressiveness and lack of speed catch up to him? Should the Sox cool off a bit on the base paths, or continue to tear them up?