Repertoires in review: Who has the best breaking ball on the St. Louis Cardinals?

Welcome to the final installment of an offseason series of posts I titled "repertoires in review." The thought process behind this series was to promote healthy discussion about the different pitch types used by the pitching staff of the St. Louis Cardinals. After sifting through PitchF/x data and often providing GIFs (via @ThePitcherList and @mstreeter06), I ended each post with a poll question in hopes of arriving at a consensus on which pitcher possessed the staff's best individual pitches.

If you have missed any of the first three posts, they can be found at the following links: 1) fourseam fastball, 2) sinker, and 3) changeup. Trevor Rosenthal, Carlos Martinez, and Martinez (again) are currently leading in the polls for fourseamer, sinker, and changeup, respectively.

Today, we turn to breaking balls, and unlike some of the other pitch types (six pitchers were included in the changeup discussion), the list of candidates is considerably shorter, with two pitchers clearly ahead of the others. Dating back to the Dave Duncan years, I have viewed the Cardinals as a fastball/changeup-driven staff, and this exercise has helped solidify that belief.

The basics (using 2015 PitchF/x data unless otherwise indicated)

Pitcher	BB Type	BB Velocity (MPH)	FB Velocity (MPH)	Velo. Difference (BB - FB)
Jaime Garcia	Curveball	73.50	91.02	-17.52
Mike Leake	Slider	81.88	91.02	-9.86
Carlos Martinez	Slider	85.92	96.53	-10.61
Adam Wainwright (2014)	Curveball	75.49	91.21	-15.72

There isn't much to make of this table other than the fact that two of the pitchers throw breaking balls of the curveball variety while the other two turn to sliders. As one would expect, curveball throwers experience a much greater velocity difference from their respective fastballs than those utilizing a slider. Other pitchers were considered (Tim Cooney, Tyler Lyons, Marco Gonzales), but as determined by their placing in the polls of the other posts in this series, they probably need a larger sample size before seriously contending in these matchups. That, or they simply have average to above-average stuff, which is just fine given their projected roles with the Cardinals.

2015 movement (in inches, courtesy of BrooksBaseball.net)

Remember: Regarding horizontal movement, a positive value means glove-side movement for right-handed pitchers, while a negative value means glove-side movement for left-handed pitchers.

Pitcher	BB Type	Dragless Horiz. Movement	Dragless Vert. Movement + Gravity
Garcia	Curveball	-6.57	-57.23
Leake	Slider	12.71	-48.71
Martinez	Slider	9.87	-33.69
Wainwright (2014)	Curveball	15.58	-58.93

In an unsurprising development, Wainwright's Uncle Charlie takes the "crown" for most horizontal and vertical movement. Being a curveball (as compared to a slider, which, by nature, is generally flatter), Wainwright was at an unfair advantage regarding vertical movement, but the amount of horizontal movement he achieves with the pitch is quite impressive (the GIF below highlights this style of movement).

2015 pertinent outcomes

Pitcher	Swing Rate	Whiffs/Swing	Ground Balls/Balls in Play	HR/FB
Garcia	39.42%	29.27%	56.25%	0%
Leake	50.93%	35.04%	39.58%	7.41%
Martinez	43.84%	32.35%	45.54%	4.55%
Wainwright (2014)	48.74%	35.33%	53.19%	2.56%

As was the case with movement, Wainwright stands out from the rest. He leads the group in whiffs per swing (in my opinion, the most important category for a breaking ball), while being at or near the top in the other three categories. While a curveball isn't generally considered a ground-ball-inducing pitch, it appears to be that way for Wainwright as over half of the balls put in play against the pitch are on the ground.

2015 results

Pitcher	AB	K	BB	BA	ISO
Garcia	23	7	0	.044	.000
Leake	80	32	4	.138	.075
Martinez	195	92	8	.174	.082
Wainwright (2014)	296	108	10	.169	.047

Again, we are dealing with small sample sizes, but since I included this table in each of my first three "repertoires in review" posts, I felt inclined to include it. Plus, it is always fun to see if overall results match up with our perceptions of the pitch after seeing its PitchF/x data. On a side note, I find it fascinating how frequently Wainwright is able to end an at-bat with a curveball. Sure, he throws his curveball relatively frequently, but even then, he only throws it ~27% of the time.

Bonus GIF Section

Garcia strikeout of Clint Barmes

It is undeniable that this curve is a bit of a hanger (in all honesty, it's really not as bad as it looks), but given the pitch immediately prior (a fouled-off 92 MPH sinker down and in), it is not all that surprising to see that the pitch locked up the knees of Barmes for strike three. I have written about the "art of the set-up pitch" before, and frankly, this curve by Garcia is a prime example of that concept.

Leake first-pitch slider to Chris Johnson

Given its location (basically right down the middle), this was essentially a get-me-over slider for strike one from Leake, but its tight spin, coupled with the fact that Johnson was not looking for a breaking ball, allowed for a successful pitch. The slider is a pitch I hope Leake turns to more often now that he will be donning the Birds on the Bat.

Martinez first-pitch slider to Brian Dozier

This slider should go down as one of the best first pitches of a start. An 87 MPH slider down and on outside corner gave Dozier, an All Star in 2015, a serious case of happy feet. The most dangerous part of this pitch is that out of the hand, and for the majority of its flight towards home, it was virtually impossible to distinguish a difference from a fastball. Should Dozier have swung the bat, it would not have ended well for him.

Wainwright strikeout of Cameron Maybin

For sample size purposes, I used 2014 PitchF/x data to discuss Wainwright's curveball, but this yakker (on October 4th, 2015) was vintage Waino. Wainwright set Maybin up with, you guessed it, a curveball down and away, and both pitches led to swings and misses. When a pitcher can successfully throw essentially the same pitch back-to-back, you know the pitch has to be filthy.

I hope you were able to enjoy my "repertoires in review" series. Please provide your thoughts, positive or negative, on it in the comments section. I will be reading them.

As always, credit to BrooksBaseball.net for the PitchF/x data and the @ThePitcherList for the beautiful GIFs (make sure to follow them on Twitter!).