Monday, July 07, 2014

Kershaw's Scoreless Inning Streak: Hershiser's Record In Sights?

Clayton Kershaw is amazing, possibly even more so on his current run of 36 scoreless innings. Well, even back when he had only 28 consecutive scoreless innings, Dan Szymborski thought Kershaw had a pretty good chance to catch Hershiser anyway (link insider only):

This year, Kershaw has held the opposition scoreless in 88.7 percent of the innings he's pitched. Going back to the start of 2013, that figure is 86.5 percent. By reference, even with the 59-inning scoreless streak included, Hershiser held the opposing team scoreless in only 82 percent of his innings pitched in 1988. While Hershiser was one of the best pitchers in baseball, he did it through impeccable location and command of his wide variety of pitches. With a fastball that can hit the 90s and a curve that violates Einstein's theory of special relativity, Kershaw more directly dominates hitters.

Assuming the 86.5 percent figure holds up on a per-inning basis, Kershaw's chances of throwing another 31 scoreless innings would be about 1.1 percent, a 1-in-100 shot. The good news is that his actual shot is better than that. No player's abilities are truly static; there's at least some variation in these underlying probabilities. Even factoring out luck, it's unlikely that Kershaw's "true" abilities are always going to be exactly those of a pitcher who holds the opposition scoreless in 86.5 percent of innings. During the course of 31 innings, having a game in which the curve is really on or the opposing hitters are seeing the ball well doesn't really even out, as it typically will over the long term. When we're talking only four (or at most five) starts, ZiPS sees Kershaw's underlying ability being a range, somewhere unknown between 77 and 95 percent.

That's good news for Kershaw, because catching a record is all about the upside. If his abilities are greater than usual over the next 31 innings, each incremental improvement significantly increases his chances. If Kershaw's underlying probability of holding the opposing team scoreless is actually 90 percent, that probability of catching Hershiser becomes 3.8 percent. If he's pitching well enough that he has a 93 percent chance of escaping each inning unscathed, his record chances become 10.5 percent.

All told, because of the uncertainty of any player's abilities at any given moment, the whole distribution comes out to an estimated 5.1 percent probability of Kershaw getting to 59 consecutive scoreless innings. Kershaw's next four starts are almost certainly going to be against the Colorado Rockies, San Diego Padres, St. Louis Cardinals and the Giants.

Going into Coors Field is always tough, but if he survives Friday's trip to Denver with the streak intact, the Padres and Cardinals have two of the worst offenses in baseball, and the Giants' run-scoring has disappeared in the ether so impressively that they may get their own Vegas show.

When I include updated projections for these team offenses, Kershaw's projected probability of 59 scoreless innings increases slightly, to 5.4 percent. Considering the difficulty of the achievement, a 1-in-19 chance is very impressive.

Matching a difficult feat is never easy -- it wouldn't be difficult if it was, after all -- but the thing about great players is they make the nearly impossible possible. While Hershiser's biggest imprint in baseball's record books will most likely still stand at the end of the 2014 season, Kershaw is baseball's best chance at making the publishers restock on white-out.

As long as we keep winning games...that's all I ask.


Fred's Brim said...

Gotta keep pitching