October 31, 2014

Statistically Speaking: Tanner Roark’s Called Strike Success

Just as the season started, Adam Kilgore of the Washington Post gave us an interesting perspective on the secret to Tanner Roark’s successful rookie season of 2013. Where many pitchers thrive on elite velocity or an unhittable trick pitch, Roark thrived on garnering called strikes and in the process, keep hitters in pitcher’s counts, allowing him to control the ebb and flow of an at bat. Given Roark’s fairly pedestrian stuff and repertoire, his ability to control the count is a crucial piece to him neutralizing lineups through pitch location, selection, and sequencing.

Considering Roark’s arsenal isn’t overpowering, the fact that he was able to get so many called strikes is amazing and a testament to not only the command and control he has on his pitches, but also their late movement, which has hitters giving up on them before they suddenly make a quick dart into the strike zone. This ability to trick hitters into not swinging rewarded Roark and the Nationals handsomely, with the righty amassing a 7-1 record in 53.2 innings pitched, with a 2.41 fielding independent pitching (FIP) and 1.4 wins above replacement (WAR) last season.

With a new season in full swing and with Roark winning a highly-contested rotation spot, has this knack for called strikes continued?

Let’s take a closer look at what Roark did last year with these called strikes compared to what he’s done in a little over 30 innings this year. In the graphic below, Roark’s 2013 called strikes, split by pitch type and batter handedness are provided on the left, with the same information for 2014 provided in the right:

TR Called

Despite the small 2014 sample, we do see that Roark so far has relied mostly upon the fastball (FF) to get his called strikes, with a handful of sliders on the outside corner to righties also helping his cause. Comparing what we can between the two seasons, we also see an interesting trend — Roark has been working lower in the zone with the fastball this season, especially against lefties. More on this later.

Focusing on 2013, we also see Roark getting called strikes from all of his pitches, but working the changeup solely against lefties and the slider solely against righties, but using a fastball-curveball combo to both lefty and righty batters, aptly using both corners of the plate in his favor.

So we have a grasp of where these pitches are coming in with respect to the strike zone, let’s now see what counts these called strikes are getting called:

Screen shot 2014-04-29 at 8.08.47 PM

Here, raw called strike counts broken down by hitting count and pitch type are provided; like before, 2013 data is to the left and 2014 data is to the right. Not surprisingly, most of the called strikes Roark are getting are in the first pitch of an at bat, both last year and this year, with some additional calls being garnered in earlier counts. With respect to pitch types, it’s Roark’s fastball that is doing most of the heavy lifting.

No huge surprise—Roark’s called strike bonanza is mostly arising from throwing first pitch fastballs. However, let’s go back to the strike zone heat map and check out how the rest of the 0-0 count called strikes shake down between this year and last:

TR 0-0

We again see his 2013 fingerprint: a fastball-curveball combo to both lefties and righties with an additional pitch (changeup for lefties, slider for righties) added in to keep things interesting, with everything just a little up in the zone. For 2014, we again fall victim to limited data, but find that for righthanded batters, Roark is now using a fastball-slider duo that he is keeping low in the zone. For lefties, we find no data — he has yet to grab a first pitch called strike to portsiders.

For the season, lefties are 1-for-11 in 0-0 counts in 2014, but have overall had more success against Roark independent of count, hitting for a .330 wOBA, compared to .288 last season. The lefty split is even more stark when comparing it to righties — this year, righties are hitting at a .264 wOBA, with 2013 seeing them hit a paltry .160 wOBA. Add to this trend the fact that the only home runs Roark has served up as a National have been against lefties and the trends seen against lefties with respect to pounding the lower part of the zone and not giving anything too good to hit on the first pitch of an at bat make more sense.

Roark’s bread and butter will always be quality strikes thrown where he wants them more so than a grip it and rip it approach; his ability to command all of his pitches and get ahead of hitters has and will continue to put him in good position to win his starts, or at least be competitive in the process.

While we find upon closer inspection of his called strike wizardry some difficulties in getting lefties to succumb to the allure of not swinging at his pitch, if his 2013 trends are to be believed, Roark still has some tricks up his sleeve when it comes to amassing more called strikes this year, in the form of throwing more secondary pitches, especially to lead off an at bat. With this working backwards and his continued mastery of the strike zone, Roark’s unexpected ascension as one of the Nationals’ more reliable starters will continue.

About Stuart Wallace

Stuart Wallace is a Contributor to District Sports Page. A neuroscientist by day, the Nevada native also moonlights as an Associate Managing Editor for Beyond the Box Score, stats intern at Baseball Prospectus, and a contributor at Camden Depot. A former pitcher, his brief career is sadly highlighted by giving up a lot of home runs to former National Johnny Estrada. You can follow Stu on Twitter @TClippardsSpecs.

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