Pitching Outside the Box (The Less Wrong Remix)

As we await the stirring finale of R.J.’s Contact Tales series (tentatively called “Who Shot R.J.?”), I thought it might make sense to revisit a post I submitted in these electronic pages just before the start of this shiny new decade.

In said post, I took a look at Matt Hanna’s work on Expected Strikeout Percentage (eK%) — a study that first appeared at DRaysBay and which resulted in this equation:

eK%=(ClStr%*.9)+(Foul%*.5)+(InPly%*-.9)+(InZSwStr%*1.1)+(OZSwStr%*1.5)

As I noted then, what’s particularly revealing about Hanna’s work is that it allows us to see (for the first time, so far as I know) the relative importance of inducing in-zone versus out-of-zone swinging strikes. The latter, if you can believe it, are actually about 2.5 times more important than the former.

Using this information, I then provided a contact leaderboard of starters from last season, weighting O-Contact% about 2.5 time more strongly than Z-Contact%.

The error I made in that post — and which reader dyross brought to our attention in the most agreeable way imaginable — is that I submitted for the reader’s consideration only the O-Contact% (and Z-Contact%). The problem with only providing the contact percentages is that it presupposes a constant O-Swing% among all pitchers — which, obviously, that’s not the case. From just the sample I picked, there’s a range of 12.30% (Sidney Ponson) to 32.80% (Hiroki Kuroda). Certainly, pitching outside of the zone in such a way as to induce swings in the first place — that’s important.

Without further ado, here’s that Top 10 list as it should’ve appeared in place of the one I actually provided. Here swinging strikes are posted as a percentage of all pitches. [TOZSS% = Total Out-of-Zone Swinging Strikes Percentage / TIZSS% = Total In-Zone Swinging Strike Percentage / SDTOZ = Standard Deviations from the Mean, Out-of-Zone / SDTIZ = Standard Deviations from the Mean, In-Zone / wAVG = Weighted Average of Standard Deviations, or (SDTOZ*2.5+ SDTIZ)/2.]

Understandably, we get some of the same names here as on the other list: Harden, Paulino, Vazquez, Dempster, de la Rosa. Those are pitchers who are able to induce swings and misses — not just misses, as in my last effort.

Newcomers to the list are: Billingsley, Liriano, Buckner, Smoltz, and Randy Johnson.

Omissions? Norris, Freddy Garcia, Gio Gonzalez, Lincecum, Sanchez.

So, like I say, that’s using all pitches as the sample.

My one concern about such a list, though, is that it could end up favoring pitchers who throw out of the strike zone with greater frequency. This, for example, is what we see Lincecum fall of the list: he throws too many balls in the zone to register a very high overall percentage of out-of-zone swinging strikes.

Really, the thing we’re probably most interested is this: pitchers who (a) throw a pitch out of the zone, (b) induce a swing with said out-of-zone pitch, and (c) receive a whiff on said swing. In other words, we’re probably most interested in how efficient a pitcher is with his out-of-zone pitches. Ideally, if he could, a pitcher would induce swings and misses on every pitch out of the zone. That’s unlikely. But here are the guys who got closes to that mark:

Ultimately, it would probably be right and good to adjust such a list for league, as it’s very likely that NL pitchers derive quite a few out-of-zone whiffs from batting pitchers. As I have very likely exhausted my skills in this particular area, I’ll just pause and reflect on the few things I’ve gotten right.