Last Year’s Best Pitch By the Numbers

How would you judge a pitch? How would you determine the best pitch in baseball?

By velocity? It’s tempting, because every mile per hour of velocity does add effectiveness to a fastball. But movement is important, and release point, or deception. Consider that Darren O’Day’s rising 87 mph four-seam fastball had the highest whiff rate of any four-seamer in baseball last year. Probably because they were expecting more sink from his arm slot, at least that was his theory.

By movement? Also tempting, movement provides us the easiest visuals. And movement is also linked to good outcomes for changeups and curves. Brett Cecil’s curve got more whiffs than any other curve, all while having three inches less horizontal movement and six inches less drop than your average curve. Weird.

So we’re left looking at results in order to judge pitches. Which results we look at are important, and how we look at them of course. Let’s set up a way to judge pitches simply and look at how they rank.

The Method

The swinging strike is very important in baseball. Pack up three of them and you’ve got a strikeout — an out that requires no help from your defenders, an automatic out. So let’s look at swinging strike rate per pitch type.

The ground ball is preached by many, and for good reason. A grounder doesn’t become a home run, and it can be defended easier, particularly if it’s hit in a predictable way. There’s evidence that pitchers with elite ground-ball rates get more of an assist from their defense than the rest of the league, and that even having one elite pitch by grounders can lead to better than league average batted ball rates. So let’s look at ground-ball rates per pitch type.

The sample for our study is every pitch thrown over 100 times last year. Z-scores add up the distance a stat is from the mean and give us a way to add up the value in grounders and swinging strikes.

But if we add up all the grounders and swinging strikes equally, we’re giving too much credit to a ball in play that still needs help to turn into an out. If you run a correlation between each pitch type’s swinging strike rate and ground ball rate to the pitcher’s overall ERA, you find that swinging strikes are, on average, twice as important as ground balls.

So our final formula for the quality of each pitch (Pitch Z Score) is basically 2*(swinging strikes z score) + 1*(ground ball rate z score), all judged against the other results in that pitch type. Sliders against sliders and curves against curves.

The Top Ten

Add it all up, and your top ten is an eclectic mix.

The Ten Best Pitches of the Year 2015

Pitcher	Pitch Type	Velocity	Total Thrown	swSTR%	GB%	Z Score
Zach Britton	Sinker	95.8	811	15%	81%	10.7
Brett Cecil	Curve	78.8	325	28%	66%	7.8
Luke Gregerson	Sinker	89.4	328	13%	68%	7.6
A.J. Ramos	Change	81.2	242	35%	56%	7.6
Aroldis Chapman	Fastball	99.4	874	19%	37%	7.4
Marc Rzepczynski	Slider	84.2	217	29%	68%	7.3
Jeurys Familia	Fastball	97.0	754	13%	63%	7.2
Darren O’Day	Fastball	87.1	349	20%	23%	7.1
Sam Dyson	Sinker	95.6	565	10%	80%	6.7
Hunter Strickland	Fastball	97.0	456	16%	43%	6.5

Z Score = 2*swinging strike z-score plus 1*ground ball rate z-score
n = 1557 pitches thrown more than 100 times last year

First of all, the 10 most successful pitches are all thrown by relievers. Go figure. But relievers do average over a mile per hour on their fastballs than starters, so they have the advantage of going all out on every pitch. They also don’t have to see a lineup more than once — batters are five to seven percent better the third time they see a pitcher. And the last factor could be the most important: they usually face batters with platoon advantages. The manager brings in the lefty to face the lefty. Every pitcher gains about a 10% advantage when they face a same-handed hitter.

You still see in this group that there are many different ways to be an excellent pitch. Zach Britton’s sinker rises to the top by harnessing the power of both the grounder and the swinging strike, though. It drops almost three inches more than the average lefty sinker, and goes about six mph faster. Maybe those things are the reason it gets three times the swinging strikes of your normal sinker! Three times. It also gets 160% of the grounders of a regular sinker. But what really makes the pitch special is that he learned it while trying to pick up a cutter. It’s a cutter grip!

Brett Cecil’s curve may actually benefit from being called a curve. Curves, on average, have an 11% swinging strike rate. Sliders have a 14% average. Cecil’s pitch has the drop of a slider and the horizontal movement of a curve, so it’s not surprising that it confounds classification. It still has twice the whiff rate of a slider, so perhaps batters have the same problem with it as PITCHf/x systems do.

A few of these pitches are expected. Aroldis Chapman‘s fastball is blazing fire — he averaged a higher velocity on it than any other pitcher in baseball. Jeurys Familia has the fifth-fastest sinker in baseball. Hunter Strickland is right there, too. Sam Dyson’s sinker is the most like Britton’s in both shape and results.

Let’s enjoy that Luke Gregerson ranking for a moment, though. He’s known for his slider, or rather his sliders, since he has three versions that he uses to keep lefties and righties equally off balance.

But here’s his sinker, a top-five pitch in baseball! Despite being slower than average and having less horizontal movement than average, even. That’s probably because Gregerson throws the slider more than half the time in any given year, and batters expect it. When they get the sinker, they swing under it. So give an assist to Gregerson’s slider for his fastball ranking.

You might have noticed that this list is all relievers. They only have to throw in short stints and enjoy higher average velocity for it. Let’s look at the starters by themselves.

The Starters

The 25 Best Pitches of the Year 2015 (Starters)

Pitcher	Pitch Type	Velocity	Total Thrown	swSTR%	GB%	Z Score
Carlos Carrasco	Curve	83.0	218	26%	52%	5.9
Joe Ross	Slider	86.9	411	26%	54%	4.9
Clayton Kershaw	Slider	84.4	925	26%	54%	4.8
Chris Sale	Sinker	94.5	1696	13%	36%	4.8
Jon Lester	Sinker	90.9	337	8%	76%	4.5
Carlos Carrasco	Slider	90.1	430	27%	45%	4.4
Tyson Ross	Slider	88.3	1447	22%	64%	4.2
Rich Hill	Fastball	90.3	201	14%	33%	4.0
Yordano Ventura	Curve	84.4	638	19%	60%	4.0
Cole Hamels	Changeup	85.2	796	26%	50%	3.9
Andrew Heaney	Slider	82.1	303	22%	57%	3.8
Max Scherzer	Slider	85.9	577	24%	47%	3.7
Jacob deGrom	Fastball	94.6	462	10%	54%	3.6
Gio Gonzalez	Changeup	82.9	473	21%	66%	3.5
Carlos Martinez	Slider	85.3	430	22%	62%	3.4
Aaron Nola	Curve	75.6	271	20%	50%	3.3
Shelby Miller	Fastball	94.2	1057	12%	38%	3.3
Jose Fernandez	Slider	84.1	314	22%	40%	3.3
Danny Salazar	Changeup	87.3	559	27%	41%	3.2
Garrett Richards	Fastball	95.7	782	9%	56%	3.2
Patrick Corbin	Slider	80.4	363	24%	44%	3.1
Jake Arrieta	Curve	79.9	531	18%	59%	3.1
Clayton Kershaw	Fastball	93.6	1824	10%	49%	3.1
Cole Hamels	Curve	76.5	401	18%	56%	3.0
Francisco Liriano	Slider	86.6	961	22%	49%	3.0

Z Score = 2*swinging strike z-score plus 1*ground ball rate z-score
n = 1557 pitches thrown more than 100 times last year

When we looked to sleepers for the 2016 Cy Young race here, we came up with Carlos Carrasco because he was a pitcher in his prime projected to be in the top 30 pitchers next year who had recently made some changes to his pitching mix. Let’s add another reason that he could win hardware next year: he has two of the best ten pitches in baseball right now in his two breaking balls. His fastball and change are above-average, too.

Carrasco makes his way with a curve and slider that are both harder than average, and so do the Ross brothers, really. But Joe Ross has a slider that drops two inches more than your average slider, while also going two mph faster. That’s a good way to miss bats.

How ridiculous is Clayton Kershaw? He picked up the slider in spring training one year and now it’s the third-best pitch in baseball. It’s probably set up by his excellent fastball (23rd on this list) and big curveball, and brought together by pinpoint command, but still. That slider has become a weapon for him.

With pitches like Chris Sale‘s sinker, Cole Hamels‘ change, and Max Scherzer‘s slider all over the list, maybe our starters are more conventional than the relievers. But there’s still Jon Lester with his 91 mph sinker wowing with a near-80% ground-ball rate, and possibly benefitting from keeping all of his pitches within a tunnel before they break in different directions. And Rich Hill’s nothing fastball — probably so effective because he throws the curve so often — also ranks highly.

Down list, there are a few young pitches to join Joe Ross‘ slider. Yordano Ventura enjoyed a bit of a late-season breakout due to throwing his hard curve more, and you can see how well that pitch ranks in the pantheon here. Andrew Heaney has been riding his sweeping slider to early success, too. Aaron Nola‘s curve doesn’t go fast, but it has three inches more horizontal movement than average, and he has great command as well. Danny Salazar’s changeup is excellent, it’s basically a split-finger, but if he can improve his command at all, he could easily break out and make us all appreciate that pitch more.

Obviously every pitch is tied to the other pitches within an arsenal, as we’ve seen as we’ve looked at the top pitches in baseball. Command matters, and the deceptiveness of the pitcher’s release point matters. How he sequences his pitches matters, too. We’re all trying to figure out how these things fit together.

But, based on two of the most important outcomes a pitch can have, you’re looking at the best pitches in baseball. And they come in many different shapes and sizes.