Game 141, Rays at Mariners
Hisashi Iwakuma vs. Alex Cobb, 7:10pm
I’ve been hoping we’d see these two starters face off against each other for a while now. In early August, I noted that Iwakuma’s splitter had induced the third-highest swing rate in MLB (for active pitchers). #2 on that list was Alex Cobb’s splitter. Cobb and Iwakuma are very similar hurlers, and both have turned into rotation mainstays despite coming to their teams without a ton of hype. They both throw four- and two-seamers and a curve (Iwakuma also has a slider, of course), but their bread and butter pitch – their weapon – is the splitter. In 2013, batters are *slugging* .296 against Cobb’s split, while they’re slugging .241 against Iwakuma’s version. For those of you who prefer tables, here you go:
(Data for this is mostly from Fangraphs; the HRs are from BrooksBaseball. I’m mixing sources in this article quite a lot, and that’s frowned upon, but different sites present slightly different info in different ways. Fangraphs calls Cobb’s pitch a change, by the way.)
Iwakuma’s splitter gets fewer swings, but then only about 1/4 are in the zone! Cobb throws a comparatively generous 37% in the pitch fx strike zone, and gets nearly double that in swings. Look at the out-of-zone swing percentage for both players. Add it up, and their slugging percentage-allowed on these pitches is easy to understand: they throw these pitches at batters shoelaces, and batters swing anyway. A lot of the time, they swing and miss, but if they make contact, they’re virtually guaranteed to hit it into the ground.
So wait, why does Alex Cobb post average HR/9 rates while Iwakuma’s been homer-prone? The difference isn’t on splitters, as we’ve seen. It’s not even about how they use their fastballs, as I suspected initially (here‘s Cobb’s FA/sinker chart, and here‘s Kuma’s). Cobb’s superior velocity may help, though neither of them are above average. Part of it probably comes down to usage – Cobb doesn’t throw that many fastballs, throwing offspeed/breaking pitches about 56% of the time. Kuma’s a bit more traditional, throwing 55% FBs and 45% everything-elses.
Both Cobb and Iwakuma have sub-3.00 ERAs this year, and while Kuma’s FIP’s a touch better, Cobb’s got the edge in xFIP; they’re essentially equals. So where’d Cobb come from? Why didn’t we hear more about him, given that several Rays prospects have had a lot of hype – from Wade Davis to David Price to Matt Moore. Jeff touched on this in his article on Cobb earlier this year, but to be fair to prospect ranking folks, he got better at each level. There’s nothing wrong with a 20 year old posting a K/9 a bit over 6 and an RA in the 3.5-4 range, but you don’t top-10 anyone for that. It obviously took Cobb a while to refine his approach, but by the time he reached AA in 2010, he was clearly a much different pitcher. Even then, he couldn’t crack the top 10 (though as John Sickels notes, that may have more to do with the other guys on the list than it did with Cobb). I have no idea if he had a similar pitch mix in the Southern League as he does now, but I can imagine scouts docking him a grade or two for it if he did. Seeing a guy come out throwing 50-60% slow stuff just doesn’t look normal – it looks gimmicky, and scouts are really good at weeding out gimmicky players – even guys who put up insane numbers in the minors. Again, I have no idea if that’s what happened, or if scouts loved him but loved Alex Colume just a tad bit more. But he’s had a great season, and if he didn’t miss a few months after being struck in the head by a line drive, we’d probably be hearing a lot more about him.
Looking forward to this battle of freakishly similar starters.
1: Miller, SS
2: Gutierrez, RF
3: Seager, 3B
4: Morales, DH
5: Ibanez, LF
6: Smoak, 1B
7: Zunino, C
8: Ackley, CF
9: Franklin, 2B
SP: Hisashi Iwakuma. Accept no imitations.
Cheers to the Pulaski Mariners who took home the Appalachian League title last night after a walk-off hit from Gabrial Franca. The fightin’ Pulaskis came back from a 5-0 deficit to win 6-5, so full credit to the bullpen (Gabe Saquilon did the heavy lift, going 5 1/3) after a shaky start by Edwin Diaz. Speaking of shaky starts by very good pitchers, Dylan Unsworth had an uncharacteristic clunker of a start for Clinton, who were knocked out of the Midwest League playoffs by Beloit. Unsworth had walked TWO batters the entire year, but walked three yesterday in just 4 innings. Congratulations, though, on a great season by Clinton.