Pitching at Altitude, Part 3: Sinkers & Cutters

Welcome to the third entry of my new data-based pitching series about the Colorado Rockies. After evaluating almost every pitcher on the roster during the extended “Crafting a Gameplan” series (which you can find here), this time we’re tackling a more widespread, fundamental topic: pitching at altitude. It’s no secret that this is a difficult thing to do, one the Rockies themselves have been grappling with for many years.

Even now, after 30 years, there doesn’t seem to be an obvious answer to pitching at high elevation. What we’re going to attempt to do in this series is use data and physics to truly understand the dynamics that make throwing a baseball at mile high elevation radically and uniquely different from any other place.

This series will be divided into six parts:

• Part 1: The General Effects of Elevation
• Part 2: Mile High Fastballs
• Part 3: Sinkers & Cutters
• Part 4: Breaking Balls
• Part 5: Changeups & Splitters
• Part 6: The Perfect Rockies Pitcher

Today, it’s time to talk about the two remaining fastball types: sinkers and cutters. I sincerely hope you enjoy the series and find it informative. If you haven’t checked out the first two entries, I recommend you do, because we went over some important data concepts in them that will be used in most (if not all) chapters, and I wouldn’t want you to get lost. I will include small explanations, but these pieces are already very long. Without further ado, let’s continue!

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After waxing poetic about four-seam fastballs in our previous entry, it’s time to wrap up the fastball section with the two other heater types: sinkers and cutters. They serve different purposes than four-seamers, and you can get caught up in pitch tagging and whether cutters are fastballs or breaking balls, but we’re going to talk about them like they’re fastballs.

Sinkers and cutters generally correspond to a more east-west approach to pitching than four-seam fastballs and their north-south nature. Is this a better fit for altitude or not? And just what kinds of sinkers and cutters translate best to Coors Field? All that and more coming up. Let’s start out with the sinkers (or two-seam fastballs, however you like to call them).

SINKERS

Ah, the sinker, the classic and typical answer for pitching at Coors Field. How do you keep your ERA down at the park where the ball flies? Well, as far as the conventional knowledge goes, by keeping it on the ground. The Rockies have often bought into this idea as well — I’m sure we all know about or directly remember the Mike Hampton signing, and how his sinker was supposed to be the antidote to the high octane run environment that was Coors Field in the steroid era... and how that worked out.

Some of the more reliable pitchers in franchise history, however, names such as Aaron Cook and Jeff Francis, followed the mold of the soft-tossing sinkerballer to good success. Even a power pitcher like Ubaldo Jiménez had his own high 90’s version of a sinker.

To this day, the Rockies often target either straight up sinkerballers or potential sinkerballers in their pitcher acquisitions, and the 40-man roster features a ton of them. When I talked about how there’s been a startling lack of good four-seamers in the upper levels of the Rockies org, that was in contrast to the abundance of sinkers. In 2022, only the Phillies threw a higher percentage of sinkers than the Rockies’ 24.4%, which was a noticeable jump from previous years for Colorado.

Did this strategy yield great results?

Not really, no. Rockies pitching as a whole wasn’t great in 2022, and those sinkers got pummeled. I’d like to point out that the last-placed rank in average exit velo against was 1.5 MPH worse than 29th-placed Arizona, which is about the same difference as the D-Backs and 14th-placed Philadelphia. That is an enormous difference, which can be partially explained by the fact that they tend to throw a lot of sinkers against opposite handed batters (so R-on-L, or L-on-R).

This is a bad idea, as sinkers are a pitch type with well known platoon splits that should be reserved for use against same handed hitters, save for truly elite sinkers, which can get away with it a little bit more. But enough talk, let’s see how the sinker has performed at Coors compared to other ballparks in recent years.

Sinker Performance at Coors

As we did with the four-seamers, let’s take a look at how sinkers have performed at Coors compared to their non-Coors counterparts in recent years. As always, Coors is going to lead to outperforming the expected stats, but we can still learn something from this basic chart:

(Run Value is the run impact of an event based on the runners on base, outs, ball and strike count. The higher, the more runs it will produce. wOBA stands for weighed on-base average; basically, OBP that takes the manner you reached base into account. xwOBA is expected wOBA, which takes walks, strikeouts and contact quality into account.)

Did any of this surprise you? Not me, and here are some of my takes from this basic data:

• Quality of contact against sinkers at Coors really isn’t all that different from sea level. They get hit a little harder, but on the ground a little more. I suspect that cancels itself out, and it’s not the main reason the wOBA jumps.
• As with four-seamers, plate discipline against sinkers is noticeably better at Coors. They get chased less, and their already low whiff rates (sinkers draw swings and misses less often than any other pitch type) go even lower.
• Sinkers are slightly better performing pitches than four-seamers at altitude. 4SF generated a .392 wOBA against, remember. Compared to that, .380 may not seem like a huge difference, but it’s decent enough over a sample of thousands and thousands of pitches.

One of the more peculiar things about sinkers at Coors is that they’re among the pitch types that see the least drastic performance decline in terms of wOBA, along with (spoilers!) sliders and curveballs. If you remember, 4SF wOBA jumped by 46 points at Coors compared to sea level, whereas sinker wOBA “only jumped by 31 points.

In a vacuum, sinkers are fine at altitude. It’s the interaction with four-seamers that suffers, because four-seamers have less carry at altitude, which means there will be less movement difference between these two fastball types. This is a dynamic we’ll explore in later entries too.

In this piece, we won’t talk about sinkers the same way we talked about four-seam fastballs, because they’re not quite as complicated from an evaluation standpoint, in particular as far as elevation and its quirks are concerned; all you’re mainly concerned about is vertical movement and velocity.

Therefore, what we’re going to do is explain the two main types of sinkers that exist in baseball, seam-shifted sinkers and true spin sinkers, and see what their characteristics are. Afterwards, we’ll explain how they deal with altitude and which one I would personally favor. Let’s start out with the true spin sinkers first.

Disclaimer: another type of sinker is the “rising sinker” that someone like Josh Hader throws, which uses seam-shifted wake and is an extremely unique profile that operates as a four-seamer. Due to its relatively niche nature, its similarity in practice to a four-seamer, and me trying to keep these pieces under reasonable length, we won’t be covering it here. A good Twitter thread from Thread Athletics’ Alex Kachler explains it here, if you’re interested.

True Spin Sinkers and Elevation

When we’re trying to create movement on a sinker, the main goal we have is trying to remove backspin from the pitch, because the more you backspin a baseball, the more it will fight gravity and stay up (as we saw in previous entries). Our objective is to replace some of this backspin with different types of spin in order to generate that drop that’s going to lead to balls being put in play on the ground.

So what is a true spin sinker? If you remember, when we talked about the Magnus Effect in Pt. 1, we mentioned how the direction a baseball spins in will directly affect its movement. That applies to all pitch types, including sinkers. A true spin sinkers is, simply put, a sinker that generates its movement courtesy of the Magnus Effect and high spin efficiency (above 90%), often associated with that running two-seam profile and lower arm slots.

You create that movement by spinning the baseball at a lower axis, closer to 3 o’clock - thus inducing side spin on the pitch and creating the horizontal movement you want. A great example of this kind of sinker is Dodgers pitcher Dustin May.

You see that movement? Filthy stuff. May’s sinker spin efficiency is often in the 92-95% range, and thanks to that low ³⁄₄ arm slot and high spin rates, he creates outlier armside run on his sinker.

This type of sinker is the one that most closely resembles a four-seamer in nature - its movement is mostly generated through spin and the Magnus Effect, and the horizontal movement is mostly a product of some of the backspin being substituted for side spin. This profile has a few particular quirks:

• It’s not as common to see good true spin sinkers from pitchers with higher arm slots. For the most part, guys who throw from higher slots tend to backspin the baseball efficiently, which directly clashes with the idea of a true spin sinker. It’s not impossible to throw a good true spin sinker from a higher slot, but it frequently requires the pitcher to be a natural at pronation (a.k.a. applying force to the inside of the ball. See: Sandy Alcántara) in order to be able to create enough side spin on that baseball at high velocity.
• Because of the more horizontal profile, true spin sinkers tend to feature noticeable platoon splits. Any sinker is going to be better against same-handed hitters, but the more the pitch favors armside run over vertical movement, the more extreme you can predict those splits to be. This is part of why it’s often so important for sinkerballers to develop a good changeup.

I think if you’ve been following the series, you will have an idea as to how Coors Field will affect the profile of a pitch whose movement is created mainly through efficient spin. But let’s check out those seam-shifted sinkers first before arriving to our final conclusions, shall we?

The Magic of Seam-Shifted Sinkers

If the best way to think about true spin sinkers is to picture that running two-seam profile, a sinker with heavy seam-shifted wake (SSW) tends to more closely resemble a bowling ball sinker, with heavy downward bite. Not all of them are like this, obviously, but the typical SSW sinker is.

Just to refresh your memory on Seam Shifted Wake, which we tackled extensively on Pt. 1, the main idea is that we can use the seams around the baseball to create pockets of higher and lower air pressure around the baseball as it travels towards home plate. An object will favor moving towards the direction of the lower air pressure pocket, so in our case we want to use the seams to create that lower air pressure in the lower half of the baseball.

This will cause the spin direction of the ball to change as it’s heading towards the plate. You can really see it here from Yankees closer Clay Holmes:

As you can see, Holmes’ sinker starts its path spinning at a roughly 1:30 axis and ends up close to a 2:30 axis as it approaches the plate. This change is created through aerodynamics, and provides sharp late movement to a pitch. Again, if you need a full explanation, I strongly recommend you check out Pt. 1.

Unlike true spin sinkers, which favor high spin efficiency numbers, SSW sinkers are often found in the lower ranges of spin efficiency, from just under 90% to as low as 60% or below. As a general rule, consider that the higher the spin efficiency goes, the more horizontally oriented the sinker will be.

Once you start getting below the 75% threshold, that’s where you’ll start finding those heavy bowling ball sinkers, such as Logan Webb and Marcus Stroman’s, among others. These types of sinkers feature a certain degree of gyro spin, which effectively means gravity has a bigger impact on the pitch’s movement. The lower the spin efficiency, the heavier the impact of gravity.

Not everyone is a candidate for this type of sinker, and the best pitchers for it tend to be guys who favor cutting their four-seam fastball at below 90% efficiency. SSW is a great way to achieve armside movement for pitchers who tend to favor supination (a.k.a. applying force to the outside of the ball at release), such as Webb or Stroman.

This is because they’ll often struggle with pronating, so getting to the inside of a sinker or a traditional changeup will be an issue for them. Instead of banging their head against the wall over and over trying to get to the inside of the ball, SSW allows these guys to apply force to the ball in a natural manner and instead use aerodynamics to create that armside movement.

Watch how Stroman releases his sinker:

See how he’s on the outside of the ball at release but still gets run on his fastball? That’s SSW for you — you can allow a supinator to still apply force to the ball in a way that feels natural to them, and use physics to create the movement.

Some quirks about SSW sinkers?

• Because they often tend to be more vertical than horizontal in terms of movement, some SSW sinkers are easier to project for smaller platoon splits. Now, they’re still sinkers, so the splits will be noticeable, but there’s a better chance here than a true spin sinker. The more vertical the sinker, the better it profiles against the same handed (again, relatively speaking).
• Unlike most true spin sinkers, SSW sinkers can often come from any arm slot. Both high slot guys, like Clay Holmes or Joe Musgrove, or low slot guys, like Logan Webb or Jake Bird, are capable of throwing this kind of sinker, even if it’s less common in high slot athletes. This makes it a versatile offering that fits many pitchers who are in the sub 90% fastball spin efficiency range.
• SSW sinkers are a fast-rising pitch type. I mean this in regards to popularity across baseball - now that teams have figured out how to manipulate seam effects to create armside movement, SSW is becoming increasingly popular, especially because it often makes a natural pairing with pitchers who excel in supination and are thus able to throw the nasty breaking balls MLB teams favor.

So in SSW sinkers, we have a pitch profile that leans more more heavily on gravity and aerodynamics than true spin direction. How does that stack up to the true spin sinker when it comes to altitude? Let’s find out.

What Sinker Profile Do We Favor?

I think you might’ve guessed this already, but let’s go over the effects altitude has on these pitch profiles. Through a combination of physics and data study from Baseball Savant, I’d narrow the list down to these general points, simplified for easier reading:

• All sinkers lose horizontal movement, but true spin sinkers suffer more heavily. This is now just data, it’s also logic: the more horizontally-based a sinker’s profile, the more its movement is going to suffer at high altitude. The sink on the pitch may be similar, but if run is the quality that makes the pitch good, that’s not an ideal profile for altitude.
• The more vertically oriented the sinker is, the steadier its profile will be. This is because on average, we can expect average vertical movement to remain similar while run will be consistently affected by at least 2-3 inches. Therefore, a bowling ball sinker whose outlier quality is its depth will offer an easier transition to altitude, as the thing that makes it good won’t be as affected.
• Low-spin sinkers with low spin efficiency are the ideal targets. Therefore, if we’re thinking about the ideal Coors Field sinker, we’re picturing a low-spin offering (below, say 2100 RPMs, ideally below 2000) with spin efficiency at least under 90% or lower. This is not a profile every athlete can get to, of course, and the kinds of pitchers who naturally lean towards this type of pitch have pros of cons in other areas. We’ll explain those in more depth in the final entry of the series, don’t worry.

And those were the sinkers. Expect them to lose run, mostly retain vertical movement, and draw even less whiffs and chases than usual. As with the four-seamers, sinkers are better suited to be complementary pitches at altitude rather than the main dish, if you will. Let’s look at cutters.

CUTTERS

Don’t we all crack a smile when we hear that ‘Pitcher X’ has been “working on a cutter” entering spring training? It’s one of the classic reports that indicates baseball’s return, right up there with “he’s in the best shape of his life” and other things of the sort.

Jokes aside, most Rockies fans will shudder when thinking about cutters at Coors Field. One of the main culprits in the implosion of the Rockies’ Super Bullpen in 2018-19 was the decline of Bryan Shaw — a very good reliever at the time coming off several workhorse seasons with Cleveland. Shaw was a spin rate darling and cutter-heavy righty who simply did not work out in purple.

Wade Davis, the Super Bullpen’s headliner, also featured a high spin rate cutter, and he got lit up in altitude as well. Just last year, cutter specialist Alex Colomé also performed poorly here, setting another terrifying precedent for the cut fastball in Mile High.

So what’s the deal? Are all cutters immediately a no-no for the Rockies? Is there a particular cutter profile that might work here? And how do we think about cutters to best take advantage of this pitch type, one that is rising in popularity in recent years?

Cutter Performance at Coors

Let’s take a look at basic results again before we talk about the physics of the cut fastball at altitude. Here’s the data for all cutters thrown at Coors Field and at all other ballparks since 2015, and what the difference ends up being:

Here we start seeing some differences from the sinkers. What did you take away from the chart? Here’s what I noticed:

• Whiff and chase rates are lower, but not drastically so. Far less than four-seams and sinkers, to begin with. These are two of the most important things in pitching: missing bats and creating strikes on pitches out of the zone.
• Cutters have performed better at Coors than any other fastball type. Even with some of the changes in movement we’ll go over very soon, cutters have outperformed both four-seams and sinkers, with a .352 wOBA against to the 4SF’s .392 and the sinker’s .380. They’re also hit softer than the other two heaters, and their run value is also over 20 points lower.

Part of this, of course, is that cutters are better performing pitches across the board than other fastballs, and even though they suffer at Coors, they still produce better results than the other two pitch types we’ve looked at so far.

But to really understand this pitch, we need to take a look at how it’s affected by the Mile High environment. Let’s go over cutter movement at altitude.

Cutters Are Unique Pitches

Cutter movement is very particular. There’s a reason good cutters tend to perform exceedingly well, and that’s because it’s just not a very intuitive way for a pitch to move. Cutters often sit in the middle ground between the carry of a fastball and the movement of a breaking ball, right in between the velocity of a heater and the velocity of a slider.

This creates a peculiar pocket of movement and velo that is often unique and difficult to square up as a hitter. Mariano Rivera, Roy Halladay, Kenley Jansen, Emmanuel Clasé, Corbin Burnes — when a cutter is great, it can be a true Hall of Fame-caliber pitch. Cutters are famous for breaking bats and handling opposite-handed hitters, and they’re rising in popularity right now as not just great pitches in their own right, but great “bridge” offerings in between the hard fastballs and nasty sweeping breaking balls MLB orgs favor.

There are many types of cutters, obviously. Some have the kind of vertical depth and the velocity you’d associate with a hard slider, some feature carry like a four-seamer would and are more similar to a true cut fastball.

You can get into pitch tagging arguments with the former category, and in many cases you’d be right. Some of the pitches that tracking systems will tag as “cutters” really belong more in the baby slider realm, but that’s part of the beauty of pitch design: no two pitches are alike. Therefore, we can’t assess a cutter through one universal lens, and we instead need to look at the physical properties of a pitch in order to see what this offering is and how it would play at high elevation.

For the sake of simplicity, however, I will be dividing cutters into the two main categories we discussed earlier: the “baby sliders” or cutter-slider hybrids, and the true cut fastballs.

Baby Sliders Translate Just Fine

When I say “baby slider”, I’m referring to something like this from Cleveland Guardians pitcher and breaking ball master Shane Bieber:

That pitch, which was tagged as a cutter, does have significant cut, but you can clearly see how it also possesses late depth akin to a slider. In fact, if I showed you that pitch without telling you it’s a cutter, would you think it’s a slider instead? I think most people would, especially given the velocity on it.

Pitches of this kind feature noticeable degrees of gyro spin. Remember when we talked about that in Pt. 1, and remember how we said gyro spin plays very well at altitude? The same logic is applied here. Cutters like that one Bieber threw would translate quite well at elevation, as their movement is not heavily spin-based.

In Shane’s case, his cutter’s spin efficiency has been in the 30-35% range over the past two years, which is firmly into slider territory. Other cutters of the sort across the league you may recognize: Marcus Stroman, Lance McCullers Jr., Shohei Ohtani, Charlie Morton, Lance Lynn, etc.

These cutter profiles are just fine at altitude, and there’s really not a lot else to say when it comes to pitch design. True cut fastballs, however? Those are a totally different story.

The Dilemma of Backspin

Unlike those baby sliders, the true cutters (we’ll refer to them as ‘cutters’ for the sake of brevity) don’t have as much gyro spin. Instead, a crucial component of this kind of movement is a heavy dose of backspin to pair with the side spin, giving the pitch that late movement towards a pitcher’s glove side to pair with the carry up in the zone.

You can see it below from Kenley Jansen:

This is not a pitch that has drop that leads to batters frequently swinging over the top of it, this is a pitch with carry that looks like it rises and cuts. Jansen is an extreme example of cut-carry movement, as his cutter is one of the greatest of all time, but many elite cutters across baseball are of this same mold.

Guys like Emmanuel Clasé (another all-time great cutter), Camilo Doval, David Robertson, Corbin Burnes and others feature this type of movement. Cutters of this style tend to feature higher spin efficiency numbers than the baby sliders we talked about earlier, often at 50% or above.

The key, again, is managing to release the pitch in a way that applies not just side spin, but also good enough backspin to the baseball in order to create vertical movement. Pitches of this kind are known to create tons of weak contact; Jansen in particular is an all-timer at inducing pop-ups and lazy flyballs.

You can see his release here:

So what is the issue with this kind of pitch at altitude? If you’ve been reading the series, you might have a good idea already.

This brand of cutter relies on backspin to give it outlier movement. This isn’t a big sweeping breaking ball; its cut is noticeable, but it’s not the lone feature of the pitch. Instead, it’s the combination of cut and carry that makes it effective.

In other words, Induced Vertical Break (IVB) really matters with this pitch. And what did we see with four-seam fastballs in Pt. 2? That’s right, IVB is cut by an average of 3-4 inches, immediately taking the subtle outlier movement of most of these kinds of cutters and turning them into something less drastic and easier to barrel up.

When paired with the fact that Coors is also going to slightly cut (ha, ha) horizontal movement, by about an inch or so, true cutters that rely on backspin and the Magnus Effect are among the pitch profiles most hurt by elevation. This is not a big breaking ball with enormous depth that sees its movement cut by 4-5 inches, this is a fastball that relies on subtle, sharp action seeing a drastic cut to its outlier movement.

As with four-seamers, cutters suffer more than breaking balls at high altitude. What’s worse, losing 5 inches out of 55 or 4 out of 18? Obviously 4 out of 18 —the percentage of movement lost is way larger.

Therefore, if you’re going to feature this pitch as a Rockies hurler, it better feature something else that makes it different. Whether that be elite velocity or -one of my favorites- a low release point to make it look flatter up in the zone, that’s your choice, but IVB can’t be the lone outlier factor here.

So that’s the cutter. Obviously, there are a lot of other dimensions to this pitch; its recent surge in popularity isn’t just because teams think these are good pitches in a vacuum, but also because they make for a perfect pairing with a bigger breaking ball.

As I talked about in my Daniel Bard piece from last season, cutters are a fantastic selection in many pitch mixes because they’re natural bridges between a fastball and the big sweeping breaking balls teams are all infatuated with nowadays. The cutter sits between the heater and the breaker both in terms of velo and movement, creating a three-headed monster that gives batters fits.

So a lot of times, a cutter’s goal isn’t necessarily to be dominant by itself, but rather serve as the glue for a larger pitch mix. That’s important to take into account when evaluating potential cutter options for altitude.

FINAL THOUGHTS

Just like four-seamers, sinkers and cutters have their uses, but they don’t produce great results at Coors Field. Ironically enough, given their reputation, cutters might be the best of the bunch, but it often takes a particular kind of cutter to succeed at altitude.

Again, though: don’t throw too many fastballs. They’re the least-productive pitches at altitude, and while they serve their purpose, overusing them will often lead to disaster.

Sinkers are quite particular at altitude, because there are certain profiles that will barely suffer (low efficiency, bowling ball types) while others that will see their outlier movement destroyed (high efficiency, running two-seamer types). Interestingly enough, the vertical movement often remains very similar, so it only makes sense to lean into that kind of shape even further.

Another interesting aspect is that the sinker profile we favor, the low spin efficiency, seam-shifted wake, bowling ball type, usually lines up very well with a cutter. What do I mean by that? Well, if a pitcher throws that kind of sinker, he probably cuts the ball at release, so a proper cutter will likely be completely natural to him.

This is where knowing each individual athlete’s motor preference (supination/staying behind the ball/pronation) is extremely important. It’s a small spoiler, but the supination-dominant pitchers are the ones that best fit the profile we’re building so far.

A Rockies pitcher who fits the bill and throws a great sinker? Righty reliever Jake Bird. His sinker averages below 2000 RPM, its spin efficiency is in the mid 80’s, and the thing is just gross:

Bird’s sinker translates just fine at altitude and, funnily enough, he also throws a good cutter, which you can see here. Bird’s cutter leans towards the true cutter with backspin type, but unlike most pitchers, his lower-than-usual release point enables him to get flatter Vertical Approach Angles (VAA, explained in Pt. 2) up in the zone and gives him a way to use it, even at altitude.

Bird’s cutter is a perfect pitch to throw up and in against lefties. As always, Magnus Effect-induced movement can’t be the outlier factor for a pitch if it’s going to translate well to Coors Field.

Now that the fastballs are done, we’ll be taking a deep dive into breaking balls in Pt. 4, tackling both curveballs and the cutter’s bigger brother, the slider. We’ll be separating them by types (sweepers vs gyro vs topspinners), and we’ll debunk some myths about how much altitude really hurts a breaking ball. I think some things may surprise you.

I hope you found this piece interesting and informative. Until next time!

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