At first glance you might think he's like a less unlucky Javy Vazquez this year. His K and BB rates are both a lot better than his 4.08 ERA with a definitively lower FIP. But check out his career ERA and FIP. The difference is minute. As always, there's a lot of noise in ERA and his FIP is actually the more telling stat here. Part of that is a 20 point bump in BABIP over his career numbers. Boston SS have fairly blah fielding win shares, though Lowell and Pedroia are second and first respectively in the AL at their positions. I'm going to go with "elevated line drive rate" as the primary issue there. All told, he's functionally the same ace he was last year.
He mows them down with heat. According to Kalk's pitch recognition algorithm, he throws a fastball and a sinker. From looking at the numbers, it looks like he's just pronating more on one, getting more horizontal break and less lift. There's only a half mph difference between the two and just a .025 difference in ISO. It's probably more appropriate to differentiate them as a four-seamer and a two-seamer. Nonetheless, getting any kind of lift on the fastball is difficult. The four seamer comes in at .091 ISO against, the two seamer at .066. This, in addition to the big time heat (he and Big Bobby have more or less the same average fastball velocity), allows him to stay in the zone well above average rates. He gets ahead easily and puts hitters in a serious bind.
As for off speed, his one weakness is that he doesn't really have an on-demand strike out pitch against righties. He doesn't have confidence throwing the change to righties regularly in the zone and as such RHB see it just 4% of the time. The curve is a good pitch that is apparently very difficult to put in play but when it does, it gets hammered. This is the strike out pitch, but as he works later in counts and into games, opposing batters will have seen it and be less likely to be overly fooled. The result is a less than stellar whiff percentage and a slightly below average ball rate. Nonetheless, the whiffs per swing rate suggests it's still very very good.
We're about to find out just how good our batters are. This is likely what a scout would call "plus plus gas" that basically no one hits HRs off of. To borrow a phrase, cackle with knowing glee if Dye and Quentin are driving the fastball early in the game.
Here things become more convoluted. He becomes a 3 pitch pitcher again, the K rate skyrockets, but the ISO against also increases. His fastball command is right on par, but the four seamer sports a .280 ISO against and while the two seamer is still (just) under .200, he throws it less frequently (about 30% less). So I might suggest sitting on the four seamer...
...except the change up comes back into play here. While the numbers make me wonder if it's actually a splitter (an 89 mph change?), it really isn't that important. The pitch itself gets a whiff nearly 20% of the time, which is as good a whiff rate I've seen on any pitch. The next best, iirc, is Dempster's slider. If you can pick it out, it's decidedly mashable, but history suggests that pretty damn difficult. The curve, meanwhile, gets a bump in whiff rate while everything else stays mostly in line.
In sum: pick one out and send it for a ride if you can, but don't expect anyone to be on base when you do.
For Your Reading Pleasure
I picked out two choice lines to check out:
Carlos Quentin vs. +93mph fastballs
Jermaine Dye vs. +93mph fastballs
I have to imagine Beckett will try to rely on the two-seamer against them given those HR numbers. We shall see. For those wondering, my math says that's a .493 ISO for JD and .485 ISO for Q! And given that, it's a serious indictment of Ozzie's choices for Leadoff Position and Bat Handler. Swish and Griffey would make far more sense.