Not that he wasn’t before, exactly. Giolito has had a brilliant season, establishing himself as a true ace in the American League. One of my favorite newish (you don’t look newish) stats to look at for pitchers is expected weighted-on-base. If you followed my stuff at BP Wrigleyville last year (and you didn’t), you’ll know I have a garden gnome who specializes in statistics, and he came up with this idea of measuring types of contact and strikes and walks at the same time. Basically the two things a pitcher can control. Of course, StatCast was already doing this and we didn’t know, because we’re morons. Happy to meet you.
Anyway, xWOBA takes the type of contact you surrender–though measured in MPH instead of hard or soft percentages like we used–along with walks and Ks to measure what wOBA you should be giving up. And Giolito ranks fifth in the AL in that, behind only the Houston duo of Verlander and Cole and the Tampa duo of Snell and Morton. Pretty nice company, if you ask me.
But, as I noted back then, Giolito had a small blip in July. I attributed some of it to his change losing some fade or arm-side run, which it had. Gio had a 5.65 ERA in July, along with his highest average, on-base, and slugging against of the season. Clearly something was off, though some fiendish left-on-base numbers didn’t help either.
Clearly, that’s been corrected in August. Gio is striking out over 14 hitters per nine, only walking two, for a tidy 7.33 K/BB ratio. Hitters are managing all of a .194 average against him in the dog days, and his ERA is 2.33 with an even more glittering FIP of 2.18. His K-numbers are best in the AL in August, and by FIP or WAR he’s been the best pitcher of the month along with Mike Clevinger and Morton again. So yeah, clearly something was corrected.
But you know that’s never good enough for me. I need answers. I need facts. I need the width and depth of it. Science matters. So what did Giolito change? Was it his change? Did it regain some of that “fade” it had lost from earlier in the year? Well, not especially.
What he has done is upped its usage, and this month Gio has almost exclusively been a two-pitch pitcher. He’s been hopped-up-on-goofballs Kyle Hendricks, almost. He’s using his four-seamer 56.6% of the time in August, and boosted his change-usage five points to 31%. So, and you can get your calculators out to check this one, nearly 88% of the time he’s throwing one or the other. The only exception is his slider, as he’s basically abandoned the curve this month.
His slider has gotten more movement in August, gaining some tilt and some sweep away from righties. But that’s not really been key to his success, as it’s generating by far the least amount of whiffs-per-swing of the season (23%, when it had been over 40% all season before).
No, the real heroes here are the fastball and change, which both major jumps in whiffs-per-swing, especially the fastball, which itself is garnering 38% in August. For a fastball is borderline obscene. So what’s going on here? Well, Gio has learned what a lot of pitchers have, and that there’s salvation at the top of the zone and above it against hitters trying to lift what’s below their waist (insert some joke about a beer belly and belt-placement here).
While Giolito hadn’t shied from going up in the zone before, he’s now living up there and above (stay hydrated!….I’m sorry). And the results are the results…
This has led to his change being more effective, as hitters scramble even more to catch up to even higher heat. So when the bottom drops out of the change, even if it’s not fading as it did in the first half, you can still hear all the air go out of their swing, and possibly their souls.
But it can’t be that simple, right? Don’t worry, it isn’t! Nothing ever is! Gio is getting all those strikeouts because he’s decided his fastball isn’t just his get-ahead pitch, but his put-away pitch to lefties almost exclusively.
Secondly, he’s decided he can throw his change to give righties the Dark One as well, which he was hesitant to do before.
You can go far with fastballs on either side of the top of the zone, and change-ups meant to look like that until the last instant. Seems like GIolito has cracked the code.