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The Pen Pals

[This is the first in a series of articles I plan to write where I look closer at the performance of the Red Sox by using sabermetrics. My thanks to Randy for allowing me to share these with you here at OTM. Please leave comments with feedback and possible rectifications of errors in analysis or stats.]

The Boston Red Sox are in possession of four of the finest young pitchers in the game. Or so we've been told. For the last 2+ years, we've been eagerly anticipating the arrival of the young guns to the big stage. Now they're here, and since over half of the season has passed, I thought it would be interesting to take a closer look at the numbers so far for our young relievers - Paps, Hansen and MDC - to try and learn more about their pitching, break apart their performance and find out how good they've really been. (For a breakdown of Lester, though a bit less extensive, see this one that I posted about a month back.)

Let's start things off with the closer. Papelbon has seemed almost completely untouchable this season, and his numbers back this up. He has appeared in 48 games, pitching 55 innings. His ERA is an amazing 0.49 and his WHIP and equally astounding 0.60. He only allows 6.1 baserunners per nine innings. The closest pitcher in this stat on the Red Sox roster is Schilling, with 10.4 BR/9. Papelbon is a strikeout machine with a K/9 of 9.3 and walks few, only 1.5/9. This gives him a K/BB ratio of 6.3, second only to Schill's 7.1. How much has our stellar defense contributed to these great numbers? Paps has a BABIP of .203 and his DIPS are a wicked 2.17. His BABIP is the lowest on the team, which does imply that Paps has been blessed with good luck. I do, however, subscribe to the idea that the ability to prevent hits on balls put in play is at least partially a result of skill, so I wouldn't say Paps has been extremely lucky, though he surely has had some luck and been aided by great defense (remember stern's catch?). What conclusions can be drawn from all this? Papelbon has been so good that he hasn't even needed all that much luck. Another evidence to just how good he has been is that he's got a VORP of 34.9, 25th in all of MLB for pitchers and the only non-starter in the top 30.

On to our new set-up man, Manny Delcarmen. MDC started the season in Pawtucket and went up-and-down until May 28 when he was called up on what seems to be a permanent basis. He's appeared in 32 games and amassed 34.1 IP. He's got an ERA of 3.93 accompanied by a very high 1.40 WHIP. He too strikes out a lot of batters, 8.7 per nine. He does walk batters now and then, 2.4/9 innings, but that's not at all terribly high. His number of walks pulls his K/BB ratio down to 3.7. His high naturally translates into allowing a lot of baserunners, and 12.9 per nine innings is rather high. A comparison might be the godawful Rudy Seanez who allows 13.6. Does bad luck play a part in MDC's so-so numbers? I would say yes, and I would do it without much hesitation. His BABIP is through the roof at .374 while his DIPS are a solid 2.63. That's a major difference. Again, I believe that skill does most definitely play a part in this, but the difference between the quality of the BABIP numbers and the DIPS numbers is so extreme that bad luck has had to have played a major part in it. Since I believe most of us have been very happy with MDC's performance so far, the fact that he's had poor luck implies that it's only going to improve once his good luck/bad luck ratio regresses to the mean.

Now, to cap things off, a look at our middle reliever and possible future closer, Craig Hansen. Like MDC, Hansen started the year in AAA. He went up-and-down one time before being called up on June 21. He, too, seems to be up for good. In 21 games, Hansen has pitched 23.2 innings. His ERA is 4.56 and his WHIP 1.35. He strikes out fewer than Paps and MDC at 7.2/9 but he as a solid, low walk-rate at 1.9/9 leading to a 3.8 K/BB ratio. He allows 12.9 baserunners per nine innings, the exact same number as MDC. The major difference between MDC and Hansen is the luck-factor. Hansen's DIPS are at 3.37 while his BABIP is a high .343. His high DIPS means that the difference between the two stats is much smaller than they are for MDC, leading to the conclusion that Hansen has had so-so luck but also not been pitching brilliantly. He has by no means pitched poorly, though. DIPS under 4 is a-ok, and DIPS under 3.5 is very good. He suffers somewhat by the quality of pitchers he's compared to in Paps and MDC.

All in all, we have two great young pitchers in Paps and MDC and a very good one in Hansen who has every possibility to become as good as his pen pals but just isn't there yet. Papelbon has been good and somewhat lucky, Delcarmen has been very good despite awful luck and Hansen has been good despite poor luck. The future does indeed look bright.

(Stats are courtesy of Red Sox Stats, and Baseball Prospectus)

(A reading tip: For an excellent and VERY exhaustive article on luck, skill and BABIP, see The Diamond Mind.)