Archive for K%+

Why Strikeouts Secretly Matter for Batters

I got my start at FanGraphs by writing Community Research articles. As you may have noticed, community authors have been very busy this season, cranking out a lot of interesting articles. One that caught my eye the other day was triple_r’s piece on the importance of strikeouts for hitters. The piece correctly pointed out, as other studies have, that there’s basically no correlation between a hitter’s strikeout rate and his overall offensive production. Strikeouts don’t matter; case closed, right? Well, not exactly.

Let me present a hypothetical situation. Say there’s a group of players who go to an “anti-aging” clinic in Florida and pick up some anabolic steroids. Let’s say these hypothetical players are named Bryan Raun, Ralex Odriguez, Tiguel Mejada, Phonny Jeralta, Celson Nruz, and Barry Bon… nevermind. Yet, after using the steroids, it appears that the group of them, on average, has not improved. The steroids didn’t improve their performance, right? But, wait — let’s also say that while visiting Florida, some of them contracted syphilis, which spread to their brains, causing delusions and severely impacting their judgment, strike-zone and otherwise. The players whose brains aren’t syphilis-addled have actually improved quite a bit, but their gains are completely offset by the losses suffered by those whose central nervous systems are raging with syphilis. So, the fact that the steroids actually do improve performance has been completely obscured by another factor that is somewhat — but not necessarily — associated with the steroids.

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Batted Ball Types and Handedness Matchups, in General

Last month, I did a two-part analysis that showed what happens — strike out-wise — when, say, a pitcher who strikes out 15% of batters faces a batter who strikes out 20% of the time. As a special bonus for you all, I included a few hundred other K%-matchup types too. I made handedness matchups central to the study, as I think it’s pretty well-established that you can expect a hitter to strike out more often against same-handed pitchers. That is, if I was trying to give an expected result for a righty batter against a lefty pitcher, I looked only at the hitter’s past performance rates against lefties and the pitcher’s history against righties. Before I moved on to performing a similar analysis on batted ball types (grounders, liners, outfield fly balls, and infield popups), I wanted to see whether handedness matchups mattered to these as well.

For this study, my sample was all non-switch-hitting batters from 2002-2012 with at least 300 PA against lefty pitchers plus at least 300 PA against righties. I’d have gone by number of batted balls, except I’m throwing some non-batted ball stats into the analysis.

Let’s get right to it — the following table shows the chances that handedness really makes no difference to each stat, according to paired t-tests:

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Stephen Strasburg, Dazzy Vance and Context

Eric Seidmen wrote an interesting article last Thursday about Atlanta reliever Craig Kimbrel’s historic strikeout pace. So far, Kimbrel is sporting a blistering 42.7% strikeout rate (K%). Even for a relief pitcher in this era, that’s incredibly impressive. But one person who commented on the story noted that there was a non-reliever approaching the same level of whiff greatness (i.e. > 30% strikeout rate).

Nationals phenom Stephen Strasburg has thrown 182 innings in the big leagues and has struck out 32.5% of the batters he’s faced. No starting pitcher who lasted any significant amount of time ever finished his career with a strikeout rate higher than 30%. The closest  is Randy Johnson and his 28.5% strikeout rate. This season, Strasburg has a 33% strikeout rate. If he were to maintain that pace, he’d be the 10th starting pitcher in history to achieve the feat and would have the 23rd such season since 1916. But take a look at that list and you’ll note that the oldest instance came back in 1984.

The problem we run into with strikeouts — like many statistics in baseball — is that the playing environment has changed over time.

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