Before I start talking about the different pitches Buehrle throws, I have to share my amazement at Buehrle's most exceptional quality: his defense. Since 2003, The Fielding Bible's DRS system has been keeping track of MLB pitchers' defensive qualities, which includes both their ability to prevent stolen bases and their fielding prowess. Using Fangraphs, we can see that Buehrle has saved, by far, the most runs of all pitchers in the 2003-2012 period, according to DRS. However, the comparison is not entirely fair, as the next pitcher on the list, Kenny Rogers, has pitched 1153 innings less than Buehrle. Kenny Rogers, another left-handed pitchers with a mid-80s fastball, might well have been even better than Buehrle at defense. Kirk Rueter, same story, but an even smaller sample size (Rueter retired after 2005). Of currently active pitchers, only Zack Greinke and Ricky Romero come close to Buehrle's quality if they keep up their current rate of saving runs through defense. Which is interesting because they don't fit the profile of soft-tossing left-handed pitchers with low strikeout rates, especially Greinke. Still, those two are his only possible peers in the art of pitcher defense.
However, a pitcher gets to show off his fielding abilities only so often, so he still has to pitch well to stay at the highest level. Buehrle, with his career ERA of 3.82, has certainly done that, despite averaging just 86 mph on his fastball. As you can guess, it's not on the strength of his heater that Buehrle has pitched so admirably all those years. Mark Buehrle instead relies on mixing his pitches, which include a four-seamer, sinker, cutter, curveball and changeup. Although hitters are unlikely to get curveballs in hitters counts, Buehrle is a true five-pitch pitcher in almost all situations. Interestingly, until 2012 he used his four-seam fastball 'backwards', which means he used it more in strikeout situations than early in the count, although he still had the sinker to set the hitter up. In terms of pitch location, Buehrle will pitch inside to righties with his cutter and outside with his sinker, using those two the other way around to lefties. The curveball and the four-seamer will be mostly on the outside part of the plate to lefties, and the changeup will be used outside to righties. Righties are more likely to get high heaters or cutters than lefties are.
Of his five pitches, the changeup and curveball get the most whiffs, the four-seamer gets the most called strikes, the sinker the most groundballs. So which is the best? Actually, it's the cutter. That's the pitch that gets him the most strikes if you combine swings with called strikes, and it also gets him the most popups. The pitch is around 5 mph slower than his fastball, but it has a lot of horizontal movement to it and is obviously thrown with precision. Want to see it in action? Because you can. The first and third pitch of that video are cutters. Buehrle also shows off a nasty changeup in that video, which looks like it should be Buehrle's best pitch. But while Buehrle prefers the change to the cutter in strikeout counts, the cutter is more useful because it can also be counted on while down in the count.
So who are Buehrle's peers? What left-handed cutter specialists do we know of? Jamie Moyer is one, but he's retired. Pettitte retired too, but he's back, so he counts. There's also Jon Lester, Jaime Garcia, C.J. Wilson and John Danks, although Wilson (sinker) and Danks (changeup) have slightly better pitches in their arsenal. Let's put their cutters in a table (less horizontal movement is more cutting action):
|Pitcher||Frequency||Strikes||Whiff/Swing||Groundballs||Velocity||Horizontal mov.||Vertical mov.|
It's obvious that Buehrle's control over his cutter is among the best, but the comparison finds him lacking in both whiffs and groundballs. I suspect this is mostly because of Buehrle's much lower velocity, as even less effective cutters like those of Cliff Lee, Jonathon Niese and Clayton Richard get more groundballs and whiffs.
I have to conclude, therefore, that Mark Buehrle is currently without any 'true peers'. His defense is likely the best in the majors and Buehrle's one of very few for whom defense actually plays an important role in getting results. Adding to that his pinpoint control and the unique way in which his cutter has success, and you can't really group Buehrle with any other pitchers that fit his profile. Buerhle, like Dickey, is one of a kind. It will be interesting to see if the Jays have Buehrle throw his pitches differently like the Marlins probably did (Buehrle threw less fastballs and more changeups last year). But whatever combination of pitches he throws, Buehrle should be fun to watch, and will gave the Jays a kind of pitcher no other team has.