Follow-up analysis on pitchers who throw less than 90mph

Last week we took a look at starters the Yankees have faced who don’t crack 90mph with their fastballs. Sometime Yankee contributor Skip subsequently encouraged me (or perhaps more appropriately, berated me) to delve further into the data:

“Larry, I just read your 90-mph pitcher post, and you’re drawing conclusions from the wrong set of data. You want to know how the Yankees do against soft-tossing starters, and yet you use the final game score and talk about the team’s overall record. I was expecting you — in a story about soft-tossing starters — to look at only how the team did against those starters. Maybe the Yanks kept a game close because of their excellent pitching, and then won the game against a hard-throwing bullpen. Looking at a final game score tells you very little about how the starter did. I know the ol’ wins and losses is ultimately what matters, but you’re not answering the question you asked. You should look at those starters’ overall ERA, FIP, K/BB, etc in order to get a true idea of how the Yanks do against them. It would probably also help to break it down into L v. R, but that’s probably a lot more work.”

Yes, it was a lot more work, but my curiosity was piqued enough that I wanted to at least try to take a look at ERA and handedness. Unfortunately for Skip I didn’t feel like calculating FIPs or K/BB ratio, but at least the ERA breakdown should help dig a bit deeper beneath the surface.

Here’s a more comprehensive table of how starters whose fastball has averaged 90mph or less during the course of their careers have performed against the Yankees in 2010, along with their handedness. In the initial study I had included Cliff Lee because Fangraphs has his career average fastball at 90, but removed him this time around. I guess Lee didn’t throw as hard earlier in his career, but he can obviously dial it above 90 when he wants to, so I’m tossing him out. I’ve also added two more games in since last week:

Though Skip poo-pooed the won-loss tally last time out, I do think that noting the Yankees’ outcomes in these games and the instances where the starter took a win or a loss is at least somewhat instructive, as it provides a broad outline of how the team fared. I’ve included the WPA scores to provide some additional context as to how the opposing team’s starting pitcher fared in these outings.

The Yankees have gone 29-15 in this 44-game sample, and the opposing starting pitchers’ cumulative record is 12-23 with nine no-decisions, six of which were Yankee wins.

The cumulative ERA from this group of starting pitchers is a fairly unexpected — at least to me — 5.25 over 243 2/3 innings. Breaking it down by handedness, the slow-pitch righties have a combined 5.88 mark in 101 1/3 innings, while the slow-pitch lefties unsurprisingly fare better — though still not quite as well as I would have presumed — with a 4.88 mark in 142 1/3 innings.

The data once again show just how much Brett Cecil has dominated the Yankees this season. His WPAs in four starts vs. NYY are 0.296, 0.186, 0.201 and 0.173, respectively. Hisanori Takahashi — a classic junkballing lefty — has also owned the Yanks, with WPAs of 0.351 and 0.399 in his two outings. In fact, those are the two highest marks by any pitcher in this group. The third-highest belongs to Kyle Kendrick and his 0.342 and fourth-highest was Josh Tomlin in his MLB debut. The worst? Trevor Cahill‘s -0.511 on August 30, and Wandy Rodriguez‘s -0.435 on June 12.

So what does all this mean? It would appear that the Yankees cumulatively don’t have quite as hard a time with soft-throwing starting pitchers than I had initially assumed. They also definitely struggle with soft-tossing lefties more than righties. And a rotation of Brett Cecil, Hisanori Takahashi and Dallas Braden would destroy the Yankees in a short playoff series.

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