Most fans of baseball seem to observe the game from a hitting-centric viewpoint. As Warren Spahn once quipped, “hitting is timing, pitching is upsetting timing.” This approach has never appealed to me — I think pitchers have a greater hand in the game than we credit them for. Aside from the fact that they succeed far more often than batters do (by a more than two-to-one ratio in most years), they can truly dominate the opposition when they fire on all cylinders.
Beyond that, pitchers make a better target for sabermetricians, as we can quantify so many elements of their game. Thanks to PITCHf/x, we can now look at pitch usage, velocity, movement, release points, locations — and, most importantly, individual result breakdowns for each offering. This can lead us down any number of analytic rabbit holes, which is where our story begins.
Because we still have a few weeks until baseball returns, I’ve decided to pass the time by constructing arbitrary “best-of” lists. Most of them wouldn’t appeal to any sane person, but I feel that many fans of the Brew Crew would like to know the answer to this question. Of the many pitches we had the pleasure of viewing last season, which stood out above the rest? A question that broad doesn’t have one right answer, but it’s an entertaining exercise regardless.
To accomplish it, I looked at pitches that appeared at least 200 times, isolating myself to those that occurred when the player was in Milwaukee. (In other words, this won’t include Mike Fiers’s time in Houston or Jonathan Broxton’s work for St. Louis.) This gave me a sample of 39 pitches to work with:
Whose quiver contained the deadliest arrow? Well, we can look at the issue a few different ways, each of which has its own merit. I’ll run through them all, with fun GIFs and full explanations, then return with a final summary.
When evaluating the quality of a pitcher, we can focus, broadly speaking, on two things: the process (think cFIP) or the results (think DRA). The same general logic applies to the pitches themselves. We’ll begin with a few metrics that will tell us how well the pitches theoretically should have performed in 2015; from there, we’ll then move to the measures of how well they actually performed.
For a pitch to blow away the opponent, it generally has to have either velocity or movement. We’ll thus begin our journey with these two categories. For this, I used the BP PITCHf/x leaderboards to find pitchers (separating starters and relievers) with 200 of each pitch type in 2015. I then found the average and standard deviations of each sample, from which I constructed velocity, horizontal movement, and vertical movement z-scores for all 39 offerings.
The pitch with the most power behind it might seem familiar:
Nelson’s curveball, which ranked above Sonny Gray and Jacob deGrom in terms of velocity, left hitters such as Aramis Ramirez guessing:
For movement, I took the sum of vertical and horizontal z-scores, to get a rough measure of overall bite. Although the top offering here might not be your first guess, it certainly deserved its spot:
Pena’s four-seam fastball didn’t have much heat, but man, could it dance. Watch how it rises and tails away from Kyle Schwarber:
Nelson saw more action than Pena did in 2015, which may explain why his curveball feels more familiar. Still, each of these offerings stood out in its own regard. As the Brewers experiment with their rotation in 2016, we’ll probably see a lot more of both the heater and the curve.
With that said, velocity and movement alone don’t make a pitch. A better line of thinking would look at the actual production of a pitch, and for that, we have a unique metric.
Pitch Type Linear Weights measure the count changes by each pitch, as well as the result when the offering ends a plate appearance, and expresses it as runs above or below average. This metric generally achieves its goal, and its selection for top Brewers pitch (on a per-100 pitch scale) probably wouldn’t get too much blowback:
Rodriguez won this contest by a wide margin — Michael Blazek’s curveball came in second, at 1.99 runs above average. Darin Ruf would probably agree with that verdict:
This shouldn’t come as a surprise, since Rodriguez’s cambio made his 2015 resurrection possible. In fact, the changeup was worth more (by this metric) on a rate basis than any other pitch, of any kind, in all of baseball. Taking note of that a few months back, Mark Simon crowned it the best pitch in the majors. Sadly, K-Rod will pitch in Detroit this season, so this changeup will no longer work in Milwaukee’s favor.
But we shouldn’t stop there, because Linear Weights aren’t perfect. Aside from the fact that they don’t necessarily reflect true talent (which we’ll discuss in due time), they treat all changes of count the same way. In the eyes of Linear Weights, a swinging strike to begin an at-bat is the same as a foul ball, since each puts the pitcher ahead 0-1. That doesn’t testify to the quality of the offering, though — whiffs are clearly better than fouls, meaning the best pitches will usually maximize the former.
For that reason, we’ll move to swinging-strike rate. Here, it’s important to take into account the different baselines, as each pitch fools hitters to different extents. To level the playing field, I created some more z-scores, using the averages and standard deviations of the whiff rates from the aforementioned velocity samples. As with the Linear Weights, the winner here won’t shock anyone:
Here, too, the leader dominated the competition: The runner-up — Neal Cott’s cutter and its 15.7 percent whiff rate— only topped the mean by 1.24 standard deviations. Based on this hilarious A.J. Pierzynski swing, I can’t argue with that:
I covered Smith’s transcendent slider back in June, and although Smith himself faded a bit down the stretch, this pitch didn’t miss a beat. Unlike Rodriguez, Smith should stick around, so this glorious breaking ball will continue dominating for the Brewers.
In the end, Nelson’s curveball, Pena’s four-seamer, Rodriguez’s changeup, and Smith’s slider disrupted plenty of hitters last year. These standout offerings gave us something to look forward to in an otherwise dismal campaign. (On that note: Later in the week, I’ll use this methodology to find the worst Brewers pitches of the 2015 season. Until then, we’ll simply have these masterpieces to keep us warm.)