On Monday I suggested that Boston find a trade partner to take Daisuke Matsuzaka off of their hands in order to open up a rotation spot and upgrade the club for 2011. While it is an option, and even a potentially viable one–please see what the St. Louis Cardinals gave up for two months of Jake Westbrook, and then try to tell me Matsuzaka is immovable–they may not be able to, or may not want to deal him. What other options are there, outside of keeping him in the rotation?
The bullpen could use an assist, as we have shown time and time again in our short existence here. There is some reason to be enthused by the idea of moving Dice-K to the bullpen, and it comes from looking at his splits. Over the course of his four seasons in the majors, Matsuzaka has been a more effective pitcher with runners on, runners in scoring position, and, in an odd twist, the more outs there are. The samples for pitching from the windup and from the stretch are the largest (nearly 1400 plate appearances from the windup, and over 1100 from the stretch with men on base) and may give us some insight into what role Dice-K is suited for on the 2011 Red Sox.
The differences in these numbers do not appear to be significant at first, but with some context they make more sense. In general, pitchers are more effective from the windup than they are from the stretch, and that is reflected in their splits with the bases empty or with runners on, respectively. In 2010, with none on, the league allowed an OPS of 712, while with men on it was 755–that is just one year of data, but that’s the way it generally has trended as of late with roughly the same differences from 2007-2009 as well. For Matsuzaka, this is then somewhat of a reverse split, but since it’s that way over the course of four seasons we can have more confidence in it being a reality for him.
With none on, from 2007-2010, Dice-K allowed hitters a line of .257/.344/.400, and struck out 21.3 percent of batters while walking 10.7 percent of them. With runners on, the batting average drops somewhat and the line is .228/.316/.380, while the punch out and free pass rates are basically the same as with none on. With runners in scoring position though (662 plate appearances) Matsuzaka is at .220/.319/.364, with strikeouts 22.7 percent of the time and walks 12 percent of the time.
Again, the differences are not huge, but since we expect them to trend in the other direction, they are worth paying attention to. Is it a focus thing? Matsuzaka is known to nibble, and his propensity for falling behind in the count after getting ahead of the hitter is well documented. Rob McQuown was kind enough to do some digging for me on this very subject, and it turns out that Matsuzaka’s pitches per plate appearance rates in each of these situations is similar–he’s still a nibbler, so the cause may lie elsewhere, such as the pitches he prefers in these situations.
The most curious part to me is Dice-K’s production depending on how many outs there are. With no outs, Matsuzaka whiffs 19.4 percent of hitters and lets 12.2 percent on via base on balls. With one out, his punch out rate climbs to 21.7 percent and his walks drop to 8.8 percent. Nearing the end of an inning, Dice-K strikes out 23.4 percent of hitters, his loftiest rate in any of these situations (though his walk rate returns to normal). There’s an emphasis on striking out the batter the more outs there are, which makes sense in many ways, especially with two outs when all you need is to retire one more batter–Dice-K certainly has the stuff to miss bats. Dialing it up from the stretch does happen as well, as research by Mike Fast earlier this season shows.
Nate Silver wrote extensively on the topic of converting starting pitchers to relievers back in 2006, when Jonathan Papelbon’s career looked like it could go in two directions. He stated, as he had researched earlier in the year for the Baseball Prospectus 2006 annual, that:
…the typical pitcher will have an ERA about 25% higher when pitching in a starting role than when pitching in relief. That is, if you take a given reliever with a 3.00 ERA, your best guess, all else being equal, is that his ERA as a starter would be 3.75.
Does that mean that the average starting pitcher has an ERA 25% higher than the average relief pitcher? No, it does not. Over the past decade or so, ERAs of starting pitchers have run about only about 7% higher than relief pitcher ERAs.
Why the disconnect? The simple answer is that starters, as a group, are better pitchers than relievers. Starting pitchers, after all, are throwing the bulk of your innings
This works in the other direction as well–Matsuzaka could, based on these results, lower his ERA by 25 percent with a move to the pen–based on this year’s numbers, that would give him an ERA of 3.54 or so. There’s also a chance that pesky walk rate would improve, again, via Silver:
Walk rate–command–is strongly associated with the consistency of a pitcher’s mechanics. Pitchers who have difficulty maintaining the same release point from inning to inning, or have trouble keeping their focus, are prone to bouts of wildness. Turning such a pitcher into a reliever can minimize this disadvantage, as he is less prone to fatigue, and may be able to get away with using just one or two pitches.
Matsuzaka’s most significant problem, walks, would not be as much of an issue out of the bullpen. Assuming an uptick in velocity and strikeouts, with more emphasis on using his very best pitches to get hitters out, Matsuzaka’s K/BB ratio would improve even if he didn’t cut into his walk rate–this would finally give him a K/BB more closely resembling the league average, which is one of those things you can’t envision him doing if he remains a starter. If he cut the number of free passes to boot, then you would have something worth trotting out from the bullpen for sure.
Between his stuff, his numbers from the stretch (relievers oftentimes enter games with runners on or in scoring position) the fact his walk rate may improve, and that he may have more value as a reliever for Boston than as a starting pitcher–especially if they find an upgrade in the rotation over the winter–Matsuzaka makes a lot of sense in a bullpen role, maybe even more so than in a trade, especially since he can also spot start if necessary and provide more innings out of the pen than your standard reliever.