The strikeout rate has increased league-wide at a rapid rate in the last decade. The primary cause? An increase in both the quantity and quality of breaking balls. Breaking balls are not the most essential pitch in the arsenal for getting strikeouts. We’ve even started to see the occasional reliever exclusively throw the breaking ball (Matt Wisler). There are also starters succeeding with the breaking ball as their primary pitch. It’s unlikely that breaker usage league-wide ever surpasses fastball usage. Still, the gap is narrowing, and having an elite breaker often means the player has a path to playing at a high level in the majors.
So what makes an elite breaking ball? That is a layered question because there are about a hundred different variants of a breaking ball. Are the best breaking balls sweepers that destroy same-handed batters? Is the best breaking ball the more consistent gyro? Or is it a slow curve? How about a spin mirror curve? A hybrid? How does tunneling factor in? There’s not an easy way to objectively determine the best breaking ball in the minors, because there are so many shape variants. Instead of breaking down the best, I’ve opted to break down five really good ones that are all different variants, and illustrate that type of variant in a clear manner.
Carlos Vargas, RHP (CLE)
Key Stats: 36.7% CSW, 73.4% Z-Swing, 34.0% Chase, 43.1% Whiff, .290 xwOBAcon
Carlos Vargas was finally moved to the bullpen this year, after years of scouts forecasting that in his future. I suspect he will be incredibly dominant in that role, given the presence of one pitch- the slider. Vargas throws the most common version of the slider — a gyro. This archetype is viable against batters of both handedness, and gets lots of out-of-zone swings and whiffs. Typically, this is not a reliable called strike pitch, and how hard it is hit, is entirely dependent on raw stuff quality, and command. They are the easiest pitch to tunnel, which is part of why most of the best starters in the game opt for a gyro.
Vargas throws perhaps the best gyro-slider in all of the minors. He throws it very hard at 90.7 MPH, and it has very low spin efficiency so it gets just -1.2” IVB with 2.1” of sweep. Gyro sliders typically need to be thrown as hard as possible (There are some exceptions where slow is better for in-zone whiffs), and move completely different from the fastball, while still forcing early swing decisions. Carlos Vargas throws his gyro harder than any other gyro-slider in the majors or minors. (Using 4” IVB to -4” IVB and 5” Sweep as limits for what qualifies as gyro).
The slider looks like the fastball out of the hand, and that is a large part of why it plays at such a high level. They share a tunnel until the last second and still manage to have very diverse shapes. The fastball is at 98.3 MPH, and the slider is 7.6 MPH slower. It should be an elite chase pitch with just 10.9” of horizontal separation from the four-seam fastball, and 14” of vertical separation. The pitch falls in all the ideal tunneling ranges so it should get elite chases as it looks just like the fastball out of the hand.
The problem with that is that he won’t get in-zone whiffs (just 28.7%) at nearly as high of a rate as he should be capable of, because the lack of velocity separation, makes it so sitting between them hits both pitches when they are located in the same spot, and Vargas, unfortunately, spends too much time occupying that same spot. This isn’t a problem with the slider command, but a fastball problem.
The slider command is fine. Vargas will work down on the bottom gloveside corner of the zone where it is best. He will catch too much plate at times, but it has all the traits needed to miss bats- except for one. The problem is his fastball location. With the fastball, Vargas has 30 grade command. He is often scattershot, but 59% of his fastballs wind up in the lower half. Of those lower half fastballs, 51.6% are to the gloveside. This is the problem. It hurts the chase rates and it hurts the whiff rates, because batters thinking fastball, see the slider off the plate as a fastball off the plate. When the slider catches too much plate, it looks like a hanging fastball that is easy to tee up and always will be swung at as a result.
The slider isn’t performing to the stuff, not because the slider is flawed, or even because of his admittedly terrible fastball shape. It’s not performing solely because of the fastball command being terrible. So how do you grade that pitch? Honestly, I don’t know. In a vacuum, it’s at least a 70, and the interactions with the fastball shape are all positive. Does fastball command matter for a slider grade? I say no, but it will affect the output and cause it to play down some. There are better gyro-sliders that maybe serve as a better example of this archetype, but Vargas is a more fun discussion, so I chose him instead to represent them.
Other Good Gyros: Jarlin Susana (Washington Nationals), TJ Brock (Toronto Blue Jays), Prelander Berroa (Seattle Mariners), Ryan Fernandez (Boston Red Sox), Roddery Munoz (Atlanta Braves)
Carlos Duran, RHP (LAD)
Key Stats: 50% CSW, 38.1% Z-Swing, 33.5% Chase, 63.6% Whiff, .224 xwOBAcon
I wrote something on Carlos Duran a few weeks ago and came away impressed with the Dodgers righty, and the slider in particular, but it was only doing research for this that I realized it might be the best breaking ball in the minors. Duran adapts his slider usage depending on the situation, and it’s a multi-dimensional weapon without the usual flaws against opposite-handed hitters as a result.
Typically, the sweeper is not a catch-all pitch. The sweeper plays for called strikes in the zone, and respectable chase rates against same-handed hitters. It’s an elite weak contact pitch against same-handed hitters as well. The problem with the sweeper is that it’s usually borderline useless against opposite-handed hitters, and in some cases is limited in two-strike counts. Duran negates those weaknesses through brilliant execution.
Carlos Duran throws his sweeper at 83.1 MPH with -1.5” IVB and 12.3” HB. It has good shape in a vacuum that is made better by his 6’7” frame and plus command, and even better deployment of the sweeper. The pitch is separated from the fastball by 11 MPH and the lack of vertical on the fastball from the high release helps hide the pitch against same-handed batters. He has extreme run in the other direction on the fastball, so you’ll never accidentally hit the slider. The combination of velocity, movement, and location difference is the primary cause of his whiff rate being over 60%. That same clearly distinctive shape makes the slider an elite called strike pitch,
The rest of the slider performance is more usage than raw stuff. Duran will change the slider usage based on the opponent’s handedness. Against right-handed batters, it’s an elite chase pitch that he zones just 38.8% of the time. Against lefties, it’s the best-called strike weapon in the sport with sub 40% Z-swing rates, and a 58.7% zone rate. Both have their niche and provide a ton of value to Duran.
I believe that Carlos Duran also happens to have plus command of the slider. Duran throws 78.3% of sliders to his gloveside against same-handed batters. The MLB average player is at 61.1%. However, when facing opposite-handed batters, that rate drops to 40.2%. Why? Armside sweepers are amazing for called strikes, and gloveside is preferred for chases. He’s not just manipulating the zone rate, but consciously choosing to use the pitch in more optimal locations based on the opposing batter.
We see this in his waste rates as well. It’s just 2.2% against lefties, and 18.3% against righties. The reason? Right-handed batters will actually chase the unhittable slider a quarter of the time. That will change at higher levels, but he’s shown the ability to throw competitive pitches when he needs to, so I’m not concerned. It’s also the distribution of his waste pitches. Nearly a third of his sliders to right-handed batters are un-competitive pitches in two-strike counts. He is getting chases at an elite rate in those spots because low-level hitters panic with two strikes, but he has the command of the slider to work it just off the plate against better hitters and not see much worse results.
The biggest concern I have with Carlos Duran is if he can consistently beat left-handed hitters. Duran will get to two strikes with the slider and tailing fastball abusing called strikes, but getting strike three looking is hard. Duran won’t get batters to whiff nearly as often with the slider against lefties- especially at the higher levels where they will better time the slider. He doesn’t get chases against lefties, so it can’t be his choice two-strike pitch against them.
The changeup could fill that niche in theory. It has great shape, but the problem is that it has just 6 MPH of velocity separation, and both the fastball and changeup, want to function in the same spot- that armside corner down in the zone. It’s a solid weak contact pitch, but he’ll need to make adjustments to consistently strike lefties out and stick in the rotation. However, the potential is obvious, and the sweeper plays at such a high level, that he only needs a decent chase changeup to be viable as a starter . The sweeper should carry Duran to the middle of the rotation outcome. He’s rule 5 eligible this year, and there is zero reason he shouldn’t be protected, even if he’s not the flashiest name.
Other Good Sweepers: Edinson Batista (Houston Astros), Hayden Wesneski (Chicago Cubs), Conor Grammes (Arizona Diamondbacks), Robert Gasser (Milwaukee Brewers), Jackson Jobe (Detroit Tigers)
Evan Reifert, RHP (TB)
Key Stats: 50.7% CSW, 42.4% Z-Swing, 43.3% Chase, 75.8% Whiff, .316 xwOBAcon
Evan Reifert’s slurve was the single most dominant pitch at any level this season. The Rays signed Reifert as a UDFA in 2020 due to the truncated draft, and he has more than proven worth the investment already. The right-handed pitcher spent most of the year at A+, where he was just great. He has found a new gear in the AFL this fall, as he has struck out 62.5% of batters and allowed just one hit. The reason for his dominance is just one pitch, the slurve.
Slurves are typically a hit or miss pitch. Some of the most dominant pitches in baseball are slurves. Julio Urías throws one, so does Dylan Cease, Shohei Ohtani as of late, and Craig Kimbrel is known as one of the best relievers of all time because of his. A good slurve is one of the most versatile and effective pitches you could ever ask for.
However, the bulk of slurves are not that effective and are classified as a slurve due to it having too little movement for a curve, and not enough velocity for a slider. The best slurves sit north of 80 MPH with depth and some sweep, but not too much of either. Those pitches are both good vacuum pitches, and they’re fairly easy to build tunnels off of. They work against batters of both handedness, but are typically crushed when left at the top of the strike zone.
Evan Reifert’s slurve checks almost all of the boxes. He throws it fairly hard at 83.3 MPH and finds that middle ground between slider and curve movement with -5.1” IVB and 4.7” of sweep. The pitch comes from a high release and has a solid tunnel with the average four-seam fastball. The stuff is good on paper, and it plays up due to deception. The results speak for themselves.
I have just one problem with the slurve. Reifert uses the slurve as his primary pitch (54.5%). This is smart pitch usage, use your best pitch more is a logical and usually correct philosophy. The slurve is objectively Reifert’s best pitch. However, the problem is that Reifert only finds the zone with his slurve 30.2% of the time.
Breaking balls with low zone rates often succeed because they get chases. Reifert gets chases so in theory, there is no problem. However, I have some concern still because the breaker is the primary. If Reifert can’t find the zone with his most used pitch why swing at all?
The count leverage in his pitch usage makes him easy to game plan against. When he is behind in the count, he uses the fastball 64% of the time. The fastball is hit harder and is much easier to make contact against. Given all that information, I think it’s clear that to beat Reifert, the best approach for a hitter is to be passive. Take until you are ahead or are in a two-strike count. Once you are ahead, be aggressive and hunt the fastball. Reifert’s tendency to lean on the breaker means that he will often fall behind if hitters aren’t swinging. This won’t stop him from finding success in the majors, but it does keep the slurve just shy of being truly elite.
Other Good Slurves: Connor Thomas (St. Louis Cardinals), Angel Felipe (San Diego Padres), Andrew Baker (Philadelphia Phillies), Chase Silseth (Los Angeles Angels), Clayton Beeter (New York Yankees)
Mason Englert, RHP (TEX)
Key Stats: 48.4% CSW, 44.5% Z-Swing, 25.0% Chase, 44.2% Whiff, .281 xwOBAcon
Most curveballs serve as a called-strike pitch above all else. They look distinct from the fastball, and hitters who sit fastball will take them as they wait for what feels like a more hittable pitch. You aren’t going to throw a freezing curve very often with two strikes. They very rarely get chases so they aren’t reliable finishing pitches. They are still valuable pitches, even if they don’t often deal the finishing blow.
The best curve in the majors by CSW is Patrick Sandoval’s called strike machine with a 56.1% CSW. He gets chases just 11% of the time but also only gets in-zone swings 23.8% of the time, and zones it 56.8% of the time. He also uses said curve just 9.3% of the time. The second best curve is Ross Strilping’s. It’s another called strike oriented pitch, and it’s thrown just 9.6% of the time. That is not unique to the two of them.
The ability of a curveball to get called strikes is directly proportional to it’s usage. Of the 46 MLB curves (Min 100 CB) with a zone-swing rate below 50% against them, only two- James Karinchak and Matthew Liberatore are thrown over 20% of the time and both of those curve give up a lot of quality contact. Can you truly call a pitch that can’t serve as the primary secondary elite? I think the answer is probably not, but that doesn’t mean that curveballs don’t provide a ton of value.
One of the best called-strike curves in the minors is easily Mason Englert’s curve. His unorthodox release point is a factor in that. Englert throws from a release height of just 5.6’ and a horizontal release of 3.3’. Wide releases encourage called strikes when located to the gloveside and help what is already a good called strike curve do its job.
The primary reason the curve gets called strikes at such a high rate, however, is the movement. Englert has -13” IVB and 13.7” of sweep at 75.8 MPH. It’s a loopy and very distinct pitch that hitters will recognize out of the hand the majority of time they see it. The fact that his other three pitches all tunnel so well also helps the curve play up above the already good shape, as by extension the curve is even more distinct due to everything else looking the same out of the hand. It also stops batters from ever sitting on the curve, even in obvious curve situations.
Mason Englert’s command over the curve also pays dividends in its performance. He zones the curve 57.1% of the time- a 99th percentile zone rate for a curveball. He isn’t just randomly throwing it over the plate either- it’s consistently down in the zone. He rarely misses high with just 14.7% of his curves there. He also avoids throwing useless waste pitches with just a 7% waste rate (17.3% MLB average) and is frequently in the shadow zone when he’s over the plate with a 42.1% rate (37% MLB average). Englert’s curve is a very valuable pitch, even if it’s not an out pitch.
Fortunately for Englert, just using the curve to get to two strikes is all he needs. The changeup is one of the best out-pitches you could ask for. He gets chases 48.1% of the time with it because it has elite depth and good fade off of a dead-zone heater. The slider is less impressive but is still a viable strikeout pitch against right-handed hitters. The lone concern with the slider and changeup is that both pitches tend to miss off of the plate. This only increases the value of the curve in getting him to two-strikes. Once he’s at two-strikes, the other secondaries are easily able to finish hitters when they are forced to be aggressive. The curve is not Englert’s feature pitch, and it probably never will be, but it’s the reason that he will be successful in the majors.
Other Good CS Curves: Simeon-Woods Richardson (Minnesota Twins), Josh Simpson (Miami Marlins), Ken Waldichuk (Oakland Athletics), Case Williams (Colorado Rockies), Alec Marsh (Kansas City Royals)
Landen Roupp, RHP (SF)
Key Stats: 43.9% CSW, 59.0% Z-Swing, 40.1% Chase, 47.1% Whiff, .316 xwOBAcon
True spin mirror curveballs are hard to find- especially in the minors. There is no easy way to search for them, because it’s not as simple as just having a mirrored spin axis (6 hours apart). They have to actually look the same despite extremely different movement profiles. Hitters often guess and track the pitch by following the seams.
The fastball and sweeper will almost never mirror because of the seam orientation and spin direction. The four-seam will appear as two vertical red lines whereas the sweeper will be skewed. The 12-6 curve, however, will also be two vertical red lines. It is very difficult to tell topspin from backspin- and spin to the right from spin to the left, as long as the seams appear on the same plane. The seam don’t have to be perfectly mirrored- just close enough. Pitching works on ranges. The orientation can vary pitch to pitch, and as long as the far-ends overlap, you should be fine.
However, spin mirroring is more complicated than what I just laid out. Pitches are not perfectly spin efficient. The fastball with perfect spin efficiency would look like two straight red lines on the ball. However, gyro spin changes that perception as those two red lines now is a red blob because they are moving in a circle. For a pitch to be an effective spin mirror it has to have both a mirrored axis, and a comparable efficiency. However, when a fastball/curveball pairing does both, greatness occurs. Aaron Nola and Framber Valdez have elite spin mirror curves and they are probably the two best curveballs in the sport. Clayton Kershaw does both of those and has identical spin rate on the fastball and curve. He’s arguably the best pitcher of all time.
I can’t definitively say if any of the curves I listed are spin mirrors given that there is no spin efficiency data for the minor leagues. I think all six of the examples have the potential to be perfect mirrors one day, but they probably aren’t there yet. Landen Roupp is one of those six, and probably the closest of the bunch to the finish line.
Roupp was one of the most dominant pitchers in the minors this year thanks to the development of his curveball which he has made into his primary pitch. The fastball is only an average pitch. He sits at just 92.9 MPH with two-seam shape. The fastball has just 9.6” IVB from a 5.3’ release height. Where it stands out is his 16.5” of fade to the armside, even if it’s not as impactful as it could be due to his generic horizontal release point.
The curve plays up off the fastball and also helps the fastball wOBAcons. He throws his curveball at 77.2 MPH with good depth at -10.9” IVB and fantastic sweep at 19” on average. By all accounts, this should be an effective but rather ordinary called strike curve based on the pitch traits in a vacuum. However, this is actually one of the best chase curves in the minors with a 40.1% chase rate.
Why? It’s a mirrored spin axis of the fastball with what is basically mirrored movement. A spin mirror is not the same thing as a movement mirror, and the latter is what Roupp currently is closer to. The curveball is thrown with a lot higher spin rates so it’s likely that his spin efficiency is ~25% higher on the fastball than curve to create the mirrored movement profiles he has right now.
Boosting the spin efficiency on the curve or reducing it on the fastball will be pivotal to Roupp’s curve continuing to be so dominant against better hitters in the majors. However, even as is, the curve is an easy plus pitch with deception and some called strike elements as well. The fastball isn’t all that, but he also offers a quality sweeper and will flash a changeup. Roupp is far from a finished product but the potentially mirrored curveball gives Roupp hope to make it as a starter in the major leagues.
Other Good CB Mirrors: Cristian Mena (Chicago White Sox), Quinn Priester (Pittsburgh Pirates), Andrew Moore (Cincinnati Reds), Noah Denoyer (Baltimore Orioles), Mike Vasil (New York Mets)