Command is a funny thing. It’s not easy to spot in the numbers. You have to watch a game and see the pitcher consistently miss his spots before you start to understand that even a guy with great walk rates may not have great command. Taijuan Walker does not have good command. He also walked 9.5% of the batters he faced in the minor leagues, a number that isn’t as far off the American League average this year (7.6%) as you might expect.
Over the last four starts, Walker has walked three batters in 29 innings. If you have an opinion regarding Walker’s command, you probably won’t change it over four starts. But Walker is still young enough, and not yet fully formed — perhaps there’s something else he’s done that can help us better understand why command is so hard to quantify. And also how likely it is that Walker can keep up this production.
The easiest thing is to just look for the thing that has changed the most over his last four starts. Let’s see if he’s simply filling up the zone. You’d think that putting balls in the zone would be a good proxy for command.
Two percentage points! Two points. He’s thrown 400 pitches in the last four games. Unless he had the good fortune of those eight pitches all coming on three-ball counts, those eight more pitches in the zone are not the difference between Walker’s expected walk total (ten) and actual (three) over the last four games.
This isn’t to say that Walker hasn’t changed anything. This might actually be a more significant change. Take a look at his pitching mix before and after our arbitrary but results-based cutoff.
He’s pretty much stopped throwing the cutter. This isn’t just a PITCHf/x thing, Brooks Baseball agrees. By that site, he threw 50 cutters over the first four games, and only ten over the last four.
Given the shape and velocity of the pitch, Walker’s cutter is a true cut fastball, not some sort of baby slider masquerading as a fastball. Fastballs are usually your command pitch, so it might seem strange at first that Walker stopped throwing a fastball and suddenly had a lurch forward in walk rate. Well, the cutter is a little different from his four-seam fastball.
First, you might notice the ball rate. There’s an easy line to be drawn from his decreased use of the cutter to disappearance of the walks. But let’s take the sanity check again. By replacing most of his cutters with fastballs, he should be getting more strike counts. But he didn’t replace all of his cutters with fastballs, only some.
In fact, if you take the ball rates of the different pitch mixes before and after the pitch mix change, there isn’t a huge change. His combined ball rate before the mix change was 35.4%. After the change? 34.5%. That’s not even four balls difference, overall. Not the reason he’s walking fewer.
Go back to the comparison of the cutter and the four-seam, though, and you’ll notice that there are other ways in which the four-seam is superior to the cutter. In fact, the four-seam is superior in all of the ways. It gets more ground balls, fewer walks, more whiffs, and more strikes. So kudos for making the switch.
Return to the first table, and you’ll see that there are two places where Walker really took a leap forward, even more than zone percentage.
His first-pitch strike rate went up, and maybe it’s been easier to get first-pitch strikes with that four-seamer. We know that first-pitch strike rate is the best walk rate peripheral, because it’s just so important to start off 0-1 instead of 1-0. Roughly 80% of the time over the last four starts, Walker has thrown that four-seamer, and nearly 70% of the time, he’s gotten a first-pitch strike. Going from 58% to 67% in that category brings Walker from around 90th among qualified starters to the top ten. That’s probably the biggest source of Walker’s improvement.
But there’s a little more to this, because command is not so simple. Walker’s out-of-zone swing rate (O-Swing%) went from 25% to 36%, a change that would bring Walker from the bottom five among qualified starters to the top ten. That’s even more impressive than his first-pitch strike improvement, and it’s also probably linked to the pitching mix change, since Walker’s four-seam has gotten reaches outside the zone 29% of the time compared to his cutter’s 23%.
So Walker probably didn’t change his ability to direct the ball over the last month. But he did improve his walk rate by focusing on two very simple things: getting strike one, and then making them reach. It’s really the best you can do if you don’t have great natural command.
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.