The Nastiest Pitches We’ll See in the World Series, Subjectively

I had slightly higher hopes for this post. Don’t get me wrong, I’m pleased with the final result. But when I first cooked this idea up, my plan was to utilize the Baseball Prospectus PITCHf/x leaderboards to pull velocity, horizontal movement, vertical movement, whiff rate and groundball rate to determine the nastiest pitches we’ll see in the World Series. But, there were a few problems.

While more velocity generally makes a pitch nastier, that’s not always true, especially in the case of offspeed pitches. More movement definitely makes a pitch nastier, but movement is hard to compare across a PITCHf/x leaderboard because a lot of it is dependent on arm slot and you get some funky values from guys who throw with funky motions.

So then, I was left with just whiff rate and groundball rate, but I actually kind of like that. Those are two of the best outcomes, and they’re the direct result of some of the things we weren’t able to capture, such as velocity, horizontal movement and vertical movement. The most dominant outcome of a pitch, for a pitcher, is a swing and miss. But not all guys dominate by getting whiffs, and so they don’t all pitch that way. Some guys dominate by getting weak contact, and ground balls yield the weakest contact of the three main batted ball types (grounders, flies and line drives). But the guys who really dominate are the ones who get the best of both worlds: whiffs and grounders.

To generate my player pools, I split up the starters and relievers. For starters, I looked at everyone who threw more than 500 fastballs (four-seamers, two-seamers and cutters) and for breaking and offspeed pitches, I lowered the threshold to 200. For relievers, my benchmarks were 200 fastballs and 50 breaking/offspeed pitches. I calculated the mean whiff rate and groundball rate for each pitch along with the standard deviation and came up with a z-score for each player. I wanted to find pitches we’ll see in the World Series that were at least one combined standard deviation better than league average at getting both whiffs and grounders. A little messy, I know, but I think it does a good enough job of capturing what I set out for, and the word “subjective” is right there in the title.

What follows is an entirely sortable table displaying the specifics of the 17 pitches which met my criteria. You’ll see the player’s name, the pitch type, the raw percentages and z-scores of each pitch’s whiff and groundball rates as well as the combined z-score, which I’ve hastily decided to label “zNAST.” Behold:

	Pitch	Whiff%	GB%	zWhiff	zGB	zNAST
Wade Davis	Cutter	35%	74%	1.62	2.25	3.87
Greg Holland	Slider	58%	58%	2.01	0.96	2.97
Jake Peavy	Cutter	28%	57%	1.22	1.54	2.76
Kelvin Herrera	Fastball	25%	51%	0.81	1.41	2.22
Wade Davis	Fastball	35%	34%	2.42	-0.29	2.13
Madison Bumgarner	Fastball	28%	30%	2.67	-0.68	1.99
Santiago Casilla	Curveball	41%	74%	0.53	1.37	1.90
Sergio Romo	Changeup	36%	75%	0.18	1.63	1.81
Tim Hudson	Cutter	31%	46%	1.75	-0.01	1.74
Santiago Casilla	Sinker	18%	68%	0.64	0.89	1.53
Kelvin Herrera	Sinker	21%	60%	1.24	0.19	1.43
Yordano Ventura	Fastball	25%	31%	1.92	-0.57	1.36
Yordano Ventura	Cutter	17%	60%	-0.62	1.97	1.34
Jean Machi	Slider	49%	47%	1.21	0.08	1.28
Jeremy Affeldt	Sinker	17%	67%	0.48	0.80	1.28
Tim Hudson	Sinker	12%	64%	-0.14	1.34	1.20
Tim Lincecum	Fastball	20%	38%	0.87	0.26	1.13

Nasty pitches are to be seen, not read about, so how about we watch some footage? I’m not gonna show you all 17 pitches, because that would be ridiculous. Let’s take a deeper look at the six pitches with a zNAST of 2.00 or greater (I’m rounding Bumgarner’s fastball up a hundredth of a point).

6. Madison Bumgarner – Fastball

This is convenient. Jeff Sullivan just wrote about Bumgarner’s fastball on Friday! Read that post if you want to know a lot about Bumgarner’s fastball. Here’s the quick rundown: Bumgarner’s throwing his fastball harder than ever, more often than ever. It’s coming in from a slightly different arm slot, and he’s throwing it up-and-in more than he has in the past. Because of that, it doesn’t get many grounders, but that doesn’t matter, as it has the highest zWhiff score of any of the 17 pitches in the table above. And most of these adjustments have happened recently, so one could argue the current iteration of Bumgarner’s fastball deserves to higher on this list. Yeah? Well, too bad. It’s not. It’s right here, as the sixth-nastiest pitch we’ll see in the World Series, which is still pretty nasty.

5. Wade Davis – Fastball

Also convenient! I wrote about Wade Davis’ complete and utter domination of all things hitter last Monday. These things tend to happen when you’re focusing on the same few teams for several weeks. The quick and dirty rundown of my Davis segment: Wade Davis, starter: bad. Wade Davis, reliever: like, the best. Wade Davis, starter fastball: meh. Wade Davis, reliever fastball: also, like, the best. It used to go 92 and now it goes 97, occasionally hitting 99. As if 99 wasn’t hard enough to hit, Davis has another pitch that’s number one on this list, as well as a pretty nasty curveball. You crazy, Wade Davis.

4. Kelvin Herrera – Fastball

Herrera’s an interesting case, because for a guy with a 100mph fastball, he actually doesn’t get that many strikeouts. Instead, the thing that made him great this year is that he didn’t allow a single home run – on any pitch. Usually, guys who throw as hard as Herrera work up in the zone to get whiffs at the expense of a few dingers. Guys without elite velocity work around the zone to generate weak contact and limit damage. Herrera does both. The average velocity on his fastball this year was 99mph, second only to Aroldis Chapman, and it had a top-15 groundball rate. That’s pretty nasty.

3. Jake Peavy – Cutter

Of the six pitches which topped this list, this is the only one I was surprised to see. But I guess I really shouldn’t have been surprised, as Peavy’s cutter was a top-10 cutter, according to our PITCHf/x run values, and it’s been good like that for a few years now. I guess I had just kind of forgotten about Jake Peavy. I think a lot of us had. Don’t forget about Jake Peavy, and definitely don’t forget about his cutter. It’s one of just two pitches we’ll see in the World Series that were at least one standard deviation above the mean at getting both whiffs and grounders this year.

2. Greg Holland – Slider

Holland’s slider doesn’t have traditional slider movement, likely due to the way he steps towards first base and falls off the mound in his follow-through. At least, that’s what the TBS announcers chalked it up to. Regardless, Holland’s slider is nasty. 58% of the time a hitter swings at Holland’s slider, he misses. That’s two full standard deviations above the mean. That’s crazy good. Greg Holland is crazy good.

1. Wade Davis – Cutter

I’m not gonna lie, I’m ecstatic this pitch came out on top, because it means I get to repurpose this GIF in another post. I think this is my favorite GIF I’ve ever created. That pitch doesn’t even look real. One of the people from the comments section of my Wade Davis post from last week accused this GIF of being altered in some way. Another described it as “Unfair. Just simply unfair.” Another said it looked like a mix between a splitter and a 12-6 curve, but thrown at 94mph. That all sounds about right. It’s got a 35% whiff rate, which is more than 1.5 standard deviations above the mean, but the craziest thing about this pitch is its 74% groundball rate, more than two standard deviations above the mean. Hearing those numbers and watching this GIF repeatedly, and my mind can’t comprehend that this pitch actually exists, or that Wade Davis is actually a human.

Guys, I think Wade Davis might be an alien.