RADIO
There is so much to look at when evaluating pitchers in 2021. The amount of data we have is incredible. At the time of this writing, there had been 186,220 pitches thrown this season.
I wanted to examine the individual pitch types and see which pitchers have been most effective with each. I am mostly focusing on two metrics here.
I will introduce my methodology before diving into the data for individual pitches. Hopefully this can bring to mind some interesting data that can prove useful for fantasy managers.
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Methodology
The first metric I analyzed is Called Strike Plus Whiff Rate (CSW%). This is well known and probably doesn't require explanation, but this is simply the percentage of total pitches that go for a called or swinging strike.
The second is Weakly Hit Rate. I put my own little spin on this one instead of just using the number from Baseball Savant or FanGraphs. Each batted ball is classified into one of six categories based on launch velocity and angle. The batted balls with the optimal combination are called barrels, and you're familiar with that. I use categories one through three to determine which contact is "weak". Those velocity and angle combinations are shown below with the red, mustard, and orange dots. These batted balls rarely go for hits, making them a very desirable outcome.
For each individual pitch (that has been thrown enough times to qualify), I found the percentile rank of the pitch's CSW% and Weak% and averaged them out to get a single grade. I will talk about the top graded names for each pitch and also provide the full datasets that include those statistics and more. We'll take a look at four-seamers, cutters, sinkers, sliders, changeups, and curveballs. Those six pitch types have made up 98% of the pitches thrown this year.
Four Seam Fastball
I'll show a quick overall pitch breakdown for each pitch, and then will display the full data that I generated for the pitch.
Here is the overall statistical breakdown on how all of the league's four-seamers have performed this year:
| Pitch Name | Usage | CSW% | SwStr% | Weak% | GB% |
| 4-Seam Fastball | 34.9% | 27.5% | 9.5% | 57.3% | 34.5% |
And here's the leaderboard (as of May 20th). Note that these tables are all searchable and sortable, although they are much easier to navigate on a PC or tablet rather than a mobile phone, so if you have the option I would recommend using one of those devices.
The best four-seamer by the combination of CSW% and Weak% has been Zac Gallen's, albeit in a lower sample size given that he's only made five starts. His fastball has a quite low 6.1% swinging-strike rate, but his command has still kept the pitch with a strong 32.9% CSW% and hitters have a crazy high 70.4% weak contact rate on it. Jacob deGrom, Lance Lynn, Tyler Glasnow, and Freddy Peralta make up the rest of the top five.
The highest swinging-strike rates on the four-seamer are deGrom, Jameson Taillon, Joe Ross, Carlos Rodon, and Brandon Woodruff.
As you saw at the beginning here, four-seamers do not generate many ground-balls. That is due to the nature of the spin and typical location of the pitch (most starters these days try to keep those high in the zone). The ground-ball rate leaders are Johan Oviedo, Ian Anderson, Garrett Richards, Shohei Ohtani, and German Marquez. These are all guys that really focus on keeping the ball down in the zone, and they have been amazingly successful with their four-seamers at getting ground-balls, although as you can see in the data, none of them are getting lots of swings and misses with the pitch.
Sinker
| Pitch Name | Usage | CSW% | SwStr% | Weak% | GB% |
| Sinker | 15.6% | 27.3% | 6.5% | 63.9% | 55.2% |
Yu Darvish's sinker is the overall winner, as it has both the highest CSW% (39.2%) and the highest Weak% (100%). He is buoyed by the fact that eh has only thrown 51 of them, barely even qualifying here. The rest of the top five: Walker Buehler, Brady Singer, Charlie Morton, Brandon Woodruff.
The sinker is the hardest pitch to get a swing-and-miss with, as you can see by the overall 6.5% SwStr% on the pitch. The highest swinging-strike rates on the sinker so far are Sandy Alcantara (13.4%), Zack Wheeler (10.7%), Domingo German (10.3%), Corbin Burnes (10.0%), and Trevor Williams (9.9%).
The main purpose of the sinker is to generate ground-balls. The highest ground-ball rates belong to Wil Crowe (78.6%), German Marquez (75%), Jack Flaherty (75%), Dylan Bundy (72.2%), and Adrian Houser (71.9%). Because of the ground-ball heavy ways, it's pretty easy to avoid the barrel with it. 17 different pitchers have sinkers that qualify here while not allowing a barrel against the pitch. The highest sinker counts with no barrels belong to Alcantara (194), Casey Mize (162), and Martin Perez (144), Pablo Lopez (105), and Matt Harvey (104).
Cutter
| Pitch Name | Usage | CSW% | SwStr% | Weak% | GB% |
| Cutter | 7.0% | 27.6% | 12.0% | 61.3% | 45.3% |
The king of the cutter is Corbin Burnes. This comes as no surprise. He has a 37.3% CSW% on his cutter and a 74.4% Weak% to go with the insane 58% ground-ball rate and 16.7% SwStr%. The rest of the top five is Trevor Bauer, Kyle Gibson, Trevor Cahill, and Corey Kluber.
You'll see some less familiar names in the above data just because not many pitchers actually throw the cutter. The highest swinging-strike rate on the cutter actually belongs to the Astros' righty Luis Garcia. No pitcher has thrown more 100 or more cutters without giving up a barrel, but Kluber, Hyun Jin Ryu, and Chris Flexen have thrown more than 150 cutters with barrel rates under 5% - pretty impressive.
This pitch is somewhat conducive to ground balls, and five players have generated GB% over 60% with the pitch: Yusei Kikuchi, Tyler Anderson, Chi Chi Gonzalez, Wade Miley and T.J. Zeuch.
Slider
| Pitch Name | Usage | CSW% | SwStr% | Weak% | GB% |
| Slider | 18.9% | 31.6% | 16.2% | 63.0% | 42.9% |
The most commonly used put-away pitch is the slider. It has the highest SwStr% of them all. The five best sliders of 2021 by my grading system: Corbin Burnes, Chris Bassitt, Tanner Houck, Jacob deGrom, and Luis Garcia. All five of those names have CSW rates above 40% with their sliders while also generating weak contact when the ball is put in play.
Changeup
| Pitch Name | Usage | CSW% | SwStr% | Weak% | GB% |
| Changeup | 11.6% | 25.1% | 14.7% | 65.7% | 52.3% |
The changeup crown goes to none other than Gerrit Cole, who has a 35.3% CSW% and a 79.2% weak contact rate. Just a short step behind him in John Means with his 37.9% CSW% and 78.3% Weak%. The rest of the top five is made up by Dylan Cease, Alcantara, and once again Corbin Burnes.
Luis Garcia grades out well with the changeup as well, giving him three stand-out pitches in this analysis. The highest swinging-strike rates belong to Kluber, Means, Kikuchi, Jon Lester, and Ross Stripling. Highest ground-ball rates are Erick Fedde, Spencer Turnbull, Aaron Civale, Anthony DeSclafani, and Bryse Wilson. Check the data table above for the full details!
Curveball
| Pitch Name | Usage | CSW% | SwStr% | Weak% | GB% |
| Curveball | 10.4% | 31.4% | 12.6% | 61.7% | 48.8% |
Our last pitch to examine is Uncle Charlie. The names at the top of the CSW + Weak Rate score are surprising ones: Jose Urquidy, Kyle Gibson, Matt Boyd, Jesus Luzardo, and Jordan Montgomery.
The best swinging-strike rates belong to Luzardo, Tyler Glasnow, Shohei Ohtani, Bruce Zimmermann, and Triston McKenzie. Pitchers that have thrown more than 100 curveballs without surrendering a barrel: Civale, Aaron Sanchez, Blake Snell, Woodruff, Rodon, Charlie Morton, Flexen, Means, Montgomery, and Jose Quintana.
That's it for this post. My intention here was more just to provide data and let you all do what you will with it. I hope this was helpful and interesting, thanks for reading!
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