Why Sixto Sanchez is Nowhere Near His Ceiling


Sixto Sanchez has taken the baseball world by storm. 

The twenty-two year old right hander has been as dominant as a rookie can, having blanked the likes of the Braves and Rays already in two of his four career starts. Sixto’s K/BB ratio is otherworldly (29/5 in 32 IP); with fantastic sequencing, and a fastball topping out at 101 MPH, he is one tough egg to crack for opposing hitters (99th percentile in xOBP in MLB).

But, after analyzing Sixto’s data, it is clear that just like an egg, his exterior can be cracked open and become vulnerable. His struggles will come and progressive teams who do their research will reveal these fissures in his armour. For example, despite it being one of his two main out-pitches, Sanchez’s slider has an expected batting average of a whopping .334; with the pitch possessing a poor xwOBA of .399 and a BABIP of .412. The problems with the slider are just one example of the many pitch related issues that Sixto has- the majority of them being masked by his high velocity sinker and fastball (96-101). Right now, he’s more protected as a rookie in a shortened season whereby opposing hitters have little to no sample size of data against him. However, these issues will definitely be exposed in a full length season, where teams get to see him multiple times. 

The purpose of this article is to break down Sanchez, diving into his strengths and weaknesses (in particular) in order to explain how he can be maximized. Given his maturity, and lethal arsenal built off his high velocity offerings, the correction of his shortcomings could only lead to one thing – the creation of a monster.

The Breakdown

As mentioned in the primer, the majority of Sixto’s issues stem from the profile of his pitches. Thus, a breakdown of each individual pitch, how they play, when and where he throws them, and how he can improve upon each one is the best way to fully paint the picture of where he is now, and where he can go.

Sixto throws five pitches and his repertoire for the most part is pretty special. Three of his five offerings (four seam fastball, sinker, curveball) register in the top 20th+ percentiles in terms of overall pitch quality per Quality of Pitch Baseball (QOP). However, it is important to note that his two most used out-pitches, the changeup and slider come up as big league average and subpar on the same QOP scale. While the lower grades on the out-pitches are noteworthy, the QOP scale does not tell the entire story in regards to overall effectiveness and traits of pitches (data does). Thus, as mentioned prior, a deep dive into each offering will shed a light on exactly where he needs to improve in order to reach his true ceiling. 

Sanchez’s arsenal and pitch locations in 2020.

Before diving into the properties of the pitches themselves (to identify issues and corrections to be made), it is important to assess the game plan of the arm; this will give the evaluator the ability to cater changes toward the most effective plan of attack for the individual player. When it comes to Sanchez, his location and pitch frequency charts clearly show that he knows exactly what he is doing when attacking hitters (great maturity for a 22 year old). 

First of all, Sanchez builds his plan of attack on the fact that he has a golden ticket of a physical profile; at only six feet tall his release height is going to be very low. This is important when coupling the release profile with his high velocity primary pitches (fastball, sinker). Why? Because hard, low vertical approach angled pitches are untouchable up in the zone. Sixto has stated a version of this many times in interviews, and based on the location chart up above, he has executed it to a tee. His maturity is also demonstrated when looking at the locations of his offspeed pitches, particularly the changeup and curve ball. Both the changeup and curveball typically showcase vertical break as a major part of their movement profiles; the fact that he mostly spots them in the middle of the zone tells an evaluator that he has tunneling in mind from the get go. The idea is that both pitches will mirror the fastball in initial appearance (up in the zone). Then, the pitches fall off the table while breaking in either direction (arm side for change, glove side for curve- his curve is gyro heavy) when the ball passes the typical recognition point for a hitter (where they have to start their swing-23.8 feet from the plate). 

The fact that Sanchez already knows how his pitches will play best (and executes them), is a major jumping off point as he trends towards ace-dom. However, knowing where your pitches play and locating them is only part of the puzzle- the pitches have to be deadly themselves.

The Arsenal- Current State and How He Can Improve:

Four Seam Fastball:

Sanchez throws his four seamer more than any other pitch (25.2% of the time). While Sanchez does a good job of mixing his pitches, the four seamer is his bread and butter; it is the pitch that made him a top level prospect. The fastball averages 98.6 MPH, fast enough to fall into the 98th percentile in fastball velocity amongst all pitchers in Major League Baseball. The pitch not only travels quickly, but has a solid movement profile as well; per Statcast, the fastball only drops 14.8 inches with gravity (plays perfectly into the ideal hard, low vertical approach angled pitch being spotted in the upper third of the zone), and the offering has a solid amount of horizontal run as well (10.4 inches to the arm side). Sanchez throws this high velocity fastball from about a 1:30 axis, with an average spin rate of 2164 RPM. 

Sanchez’s fastball tilt, seam orientation, and spin profile presented via Baseball Cloud’s BallR.

While the fastball is clearly elite, garnering a xBA of .213, it is not without its weaknesses. Despite the low expected average, the pitch has an xSLG of .681 — no bueno. Essentially, the probability model is saying that when it gets hit, it will probably be hit very hard. So how can this be prevented? The first place to start is by looking at the elephant in the room, the fastball spin rate. Sitting at an average of just 2164 RPM, it is almost 100 RPM below big league average, and between 200 and 300 RPM below the average spin rate for his velocity range (96-101). This is a glaring problem. As mentioned prior, Sixto’s short stature and high velocity suggest that he should have a fantastic vertical approach angle (descent angle of the ball traveling from hand of pitcher to the plate, vaa). Essentially, the flatter the angle, the harder it is for hitters’ vertical bat angles to line up with the angle of the pitch (i.e. more whiffs and pop ups). Typically, high velocity fastballs have higher spin rates (which also plays into the vaa). The reason that this is important is due to the Magnus Effect, which in short is the idea that a faster rotating ball will push air downward, giving it more lift (helping it play up in the zone by not dropping). Sixto’s fastball’s low spin rate means that it is not being aided as much by magnus force; it has the potential to drop down into the zone more than say Trevor Bauer’s fastball, which averages over 2700 RPM. This is a problem, as it counteracts the rest of the pitch’s profile (how it should be playing-up, which is also how he throws it), and it takes away from the danger of the pitch (whiff rate of 33.3% at 98.6 MPH avg, Bauer whiff rate of 23.8% with avg velo of 93.6 MPH). While these grip strength numbers are proprietary, Sixto will probably have to work on his finger strength to increase the friction between his fingers and the ball — thereby, he can bolster the spin profile. While cutting the ball can also add raw spin, I believe that this is not the best solution for Sanchez, as he already throws the fastball at an 88.1% spin efficiency. Further cutting of the fastball would take away from its horizontal run (part of what makes his fastball special). 


Sixto’s second high velocity pitch is his sinker, which averages a speed of 96.5 MPH (slower than the four seam). Sanchez throws the sinker at a similar rate to his four seam fastball (23.3% SI vs 25.2% FB). Sanchez’s sacrifice in velocity on the sinker is made up for with its break profile; the sinker runs 17.4 inches on average (elite), and drops 24.7 inches (gravity included) coming from a 1:45 ish axis. This combination of velocity and movement profile are good enough to give it a QOP rating of 4.91 (91st percentile in break- 4.66 is 80th percentile for overall quality).

However, despite the pitch profile on the surface, the data, probability models, and in-game results suggest that the sinker is far from special. The first statistical red flag with Sanchez’s sinker is the fact that batters are hitting .280 on balls put in play on the pitch. Not only that, but the expected batting average on the pitch is .264 (league average is .250). With a league average xwOBA added on, Sixto’s sinker is really not a very dangerous pitch (as probability models and in-game results show). 

Sixto Sanchez’s sinker profile (tilt, spin, seam orientation) as presented by BallR.

So, how does he fix the pitch? A good place to start would be his efficiency. Much like the fastball, it hovers in the high eighties. While cutting a fastball can add additional raw spin, it takes away from the potential break profile (a sinker is designed to move in order to induce soft contact). Therefore, Sanchez’s cutting of the sinker is actually preventing it from – sinking. If Sanchez were to improve his spin efficiency on the pitch, it would result in more vertical and horizontal movement on the offering due to there being more active spin on the pitch. In other words, its movement profile would be drastically different from the fastball, making it a lethal option. The second (and final) major issue with the sinker is the same major problem as his fastball, its lack of spin. Sanchez likes to locate it in the middle third of the zone in order to generate either a whiff or soft contact, something we have seen from guys such as Dustin May. The idea behind this is to generate a high velocity, faster playing sinker with an emphasis on arm side run. The only difference is that May gets 288 more RPM than Sanchez does on the pitch; the tighter spin rate means more spin induced run (ideal). The fix to this issue is the same as his fastball — improve finger strength and maximize friction on the baseball. If he accomplishes this and fixes the efficiency, the sinker could become a deadly weapon.


Sanchez’s slider is the most problematic pitch in his arsenal, and quite frankly will be a major factor in how he ends up projecting due to its frequency of use (18.3% total, 25.8% vs righties). As mentioned in the primer, Sanchez’s slider has been hammered relative to his other pitches (.412 BABIP, .334 xBA, .399 xwOBA, .527 xSLG). The offering has an average velocity of 89.2 MPH (98th percentile in velocity), with a solid horizontal break profile of 4.6 inches of break (1.4 inches more than MLB average), and 29.7 inches of vertical drop including gravity (1.4 inches less than MLB average). He throws the pitch from a high 11:00 tilt, which results in it looking more like a fastball out of the hand, while sacrificing potential horizontal break with the greater vertical tilt. The movement profile itself can be attributed to its average spin rate of 2371 RPM, with an efficiency of 29.7% (solid gyro number).

Sanchez’s slider characteristics as shown through BallR.

The issue with Sixto’s slider mirrors exactly what is holding him back on his high velocity pitches: the spin rate. A slider’s main focus from a spin perspective is its emphasis on gyroscopic spin. What gyro spin does is eliminate the majority of spin induced movement, preventing a lot of vertical break and allowing the pitch to still move laterally due to the axis of the pitch being tilted slightly to the side. Sixto’s slider spin rate is where we want to see fastball spin, not slider spin (great sliders can reach over 3000 RPM). This means that it is far too slow rotationally for the magnus effect to do its magic (due to the gyro profile of the pitch), and for the useful spin to create elite horizontal break. This means that gravity is pulling the ball down more than intended, resulting in the pitch falling into vertical bat angles (more than a high spin, elite slider), instead of playing flatter with glove side action as it is supposed to. Sanchez gets away with his slider sometimes due to the change in velocity fooling hitters, but if he doesn’t fix his spin rate; this will be a pitch that hitters will tee off on a year or two down the line. Given Sixto’s relatively low spin rates on almost all of his pitches (coupled with high percentile velo), it appears pretty obvious that his finger strength needs to be drastically improved. If it isn’t, he may have to scrap the slider altogether down the line.


This sequence shows exactly why the curveball has been effective for him early in counts- it sets up the late fastball.

Sanchez’s curveball is his most dangerous pitch according to pretty much all projection models out there (.071 xBA, .129 xSLG, .082 xwOBA). Not only that, but the results on the field have supported the projections with a BABIP of .200, a whiff rate of 41.2%, batting average of .143 against it — the pitch has been nearly unhittable. The reason behind this is the curveball’s unique profile. While most curveballs focus on tunneling in relation to fastball profile before falling off the table (12/6 action mimics 12:00 FB axis), Sanchez’s curveball tilt (roughly 8:30) compliments a slider – his more commonly used breaking pitch much more. Sanchez throws the pitch with an almost identical grip (to his slide piece), and snaps the wrist very similarly. This has resulted in a gyro-spin heavy curveball, that mimics the slider from a spin perspective (thus fooling hitters). The only difference between the two (outside of axis) is that Sanchez is slightly more efficient on the curveball (38.9%), which allows it to gain an additional 3.5 inches of horizontal break (axis contributes), and nearly 10 inches more in gravity included drop than his slider. The end result is that a hitter sees a slider out of the hand, only for it to reach the plate a little slower (85.4 avg MPH vs 89.2 on SL), and drop and break a little bit more than expected (hence the sky high whiff rate). 

Sixto’s curveball profile as depicted by BallR- Sanchez’s curve is extremely gyro heavy with its low amount of efficiency- it makes the pitch look a lot like a slider out of the hand, while ending up slower and with more break.

In regards to improvement on the pitch, the only thing I would like to see added (similar to every other pitch) is excess spin (2461 RPM average on the curve). With the added efficiency in comparison to the slider, added spin would result in even more break, which could make it an even deadlier option. Outside of that, he should continue to throw the pitch in the exact same way – it is an unusual ploy (mimicking SL not FB) that fools hitters on a regular basis.


Sixto’s changeup is his most commonly used secondary offering and has been absolutely dominant thus far since being called up. Interestingly enough, according to Quality of Pitch Baseball, the changeup’s physical profile is relatively average when compared to the rest of Major League Baseball. When looking at the pitch’s break profile, it is definitely not a world beater; the changeup drops an average of 1.5 inches and has about 2.8 inches more run than the average MLB changeup. Despite that, hitters are only hitting .185 on changeups put in play. The projections also back the results on the field, with the xBA sitting at a miniscule .158, and xSLG hovering at a lowly .178. So why is it so effective? For starters, the pitch looks a lot like the sinker out of the hand. Sanchez throws a changeup with a spin profile that mimics a two seam fastball/sinker (similar seam orientation, 2:00 axis on CH, 1:45 on SI) – when a hitter picks up the spin, it looks like a sinker. Sanchez also does a fantastic job of killing lift on the pitch. With an average spin rate of 1813 RPM, it is finally a pitch of his that benefits from a low spin rate. The low spin with similar seam orientation to the sinker also makes the pitch travel much slower than the hitter expects (89.3 MPH CH vs 96.5 MPH SI), with it dropping off the table more as well due to less magnus force keeping it up. 

Sanchez’s changeup as depicted by BallR.

In regards to adjustments on the change: there aren’t any really. The pitch isn’t designed to have an elite movement profile; it is meant to fool hitters based on its seam orientation and axis, resulting in whiffs and mishits due to bad timing. 


Over his first five starts, Sixto Sanchez has proven that he has the goods to be an ace in the league for a decade or more. However, as shown in the breakdown of his pitch profiles, the raw data, and projection models, there are many flaws that need to be addressed for him to stay at the top. Right now, Sanchez is getting away with the lack of spin on his pitches, and overall lower quality of his slider due to ‘freshman syndrome’. However, this will not last. Big league hitters are too good to be beat by pitches that aren’t up to par. Sanchez has the physical profile and stuff to be an ace, but he will have to work hard on improving his spin (on all pitches but the changeup) if he wants to remain successful. After all, there are plenty of guys that throw 98 and get shelled due to poor pitch profiles. Let’s hope Sixto does not end up one of them.

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