The Rays Way: Extreme sinker splits

When you think about what makes a good modern pitcher, there are probably a million thoughts that flood your mind. Velocity, pitch shape, sequencing, command, stamina, times through the order and exposure, the list goes on and on.

Some of these pitching concepts are very advanced, and require a multidisciplinary approach to understand. Even the smartest pitching minds are still working on them. But one of the most important parts of pitching is very simple to grasp, and maybe more importantly, is very easy for a player to change: pitch usage.

How often should a pitcher throw his fastball? To whom? In what location? What about his breaking ball?

These questions are easy to comprehend, but can be tricky to answer. The Rays, however, seem to have a very specific plan of attack when it comes to pitch usage and the way they’re able to adjust usage plans to cater to the strengths of their pitchers is a big part of how they constantly churn out great pitching staffs. To illustrate, lets dive into how Rays pitchers as a whole use sinkers.

The Rays sinker strategy

First, it should be known that the Rays as a whole don’t throw a ton of sinkers. Per Baseball Savant, they ranked in the bottom 10 teams in sinker usage during the 2021 season. So while the Rays don’t exactly have a sinker-heavy pitching staff, the sinkers that they do throw are used in a very particular way:

The Rays love to throw sinkers to same-handed hitters, and hate to throw sinkers to opposite-handed hitters.

What I mean by this is that many of the right-handed Rays pitchers throw substantially more sinkers to righties than they do to lefties, with the opposite being true for left-handed pitchers. I’ve pulled the numbers (from Baseball Savant’s search feature) to back up this point as well:

• 73.4% of all of the sinkers thrown by Rays right-handed pitchers were thrown to right-handed batters, the 3rd highest mark in baseball.
• 45.7% of all of the sinkers thrown by Rays left-handed pitchers were thrown to left-handed batters, the 4th highest mark in baseball.

These rankings show that the Rays sit atop the league in differing their sinker usage depending on batter handedness. The only other team who ranked in the top 5 in both of those stats was the Boston Red Sox. Former Rays executive Chaim Bloom was recently hired to be the GM in Boston, which suggests that it may not be a coincidence that the Rays and Red Sox share similar pitching philosophies.

Side note: the reason the 45.7% left-on-left percentage is so much lower than the 73.4% right-on-right percentage, yet still ranks so highly, is simply because there are many more right-handed batters than there are lefties in baseball. Meaning there are not as many opportunities for lefties to throw sinkers to lefties, hence the lower percentage but similar ranking.

While these marks are representative of total team stats, we can also look at individual players in this regard. The table below shows the 10 pitchers who had the largest discrepancy between sinker usage to righties and lefties in 2021. (minimum 300 sinkers thrown):

The final column which is labeled difference, is simply calculated by subtracting a pitchers sinker % to righties from their sinker % to lefties. Also, the absolute value of this calculation is used, in order to put left-handed pitchers and right-handed pitchers on the same scale.

Only three Rays pitchers threw 300 sinkers in 2021, and two of them land in the top 10 of this list in Josh Fleming and Ryan Yarbrough. The other Tampa Bay pitcher to meet that threshold was Andrew Kittredge, who also split his sinker usage up between lefties and righties, but to a lesser extent (9.6% difference).

Josh Fleming is particularly interesting to me because his 72.4% sinker usage to lefties was actually the highest mark among all MLB lefty starters in 2021 and by a wide margin. The organization clearly trusts that pitch to do the bulk of the lifting against left-handed hitters for Fleming, and his career 36:3 strikeout-to-walk ratio against lefties (37 IP) is a good indication that the strategy is working.

But wait, there’s more!

One of the better ways to get insight into an organization’s pitching philosophies is to compare pitch usage trends for newly acquired arms. In recent years, the Rays haven’t acquired too many pitchers who lean on sinkers, but there are two relatively minor moves I want to highlight here: the acquisitions of right-handers Aaron Slegers and Chris Mazza, two pitchers with good sinkers and deep arsenals.

Below you’ll find two tables, one for Slegers and one for Mazza. I’ve split up their sinker usages so that you can see the difference in how they are using that pitch after arriving in Tampa Bay. Keep in mind both of these pitchers are right-handed.

Upon arriving in Tampa Bay both hurlers saw their sinker usage to righties tick up while their sinker usage to lefties came down, suggesting once again that the Rays have a very specific plan when it comes to sinkers. The Rays also signed both Slegers and Mazza to minor league deals for 2022.

Because pitch mix is relatively easy to change, compared to other characteristics, the Rays may think about sinker usage by handedness as a quick and easy way to help pitchers optimize their arsenal. This makes me think about the two newest Rays signings, Brooks Raley and Corey Kluber, both of whom use a sinker as their primary fastball.

In 2021, Raley posted a sinker usage difference of 20.9% in favor of lefties while Kluber was at 20.2% in favor of righties. This means that both pitchers are already comfortable at mixing up their sinker usages depending on batter handedness, exactly what the Rays pitchers have been doing. I think there is a chance that those percentages could rise even further once they join the staff in Tampa Bay.

Photo by Julio Aguilar/Getty Images

Why do the Rays use sinkers in this way?

Now that we’ve identified what the Rays have been doing with sinkers, lets take a crack at answering why.

The logical place to start is to compare the results on league-wide sinkers depending on batter handedness. The two tables below show the difference that batter handedness makes when comparing various batted ball metrics against sinkers. The first table averages the results on every sinker thrown by a right-handed pitcher in the 2021 season:

The second table is set up in the exact same way, but instead is representative of sinkers thrown by left-handed pitchers:

These league-wide numbers tell us that throwing sinkers to same-sided hitters leads to more groundballs, softer contact, and overall better results. This discrepancy that we see in the splits is very large in comparison to other pitch types. In 2021, no other pitch type saw larger wOBA splits than did sinkers. It’s an extremely platoon-heavy pitch.

I will say that this may not be a one-size-fits all conclusion, as every sinker is different and there may be some sinker shapes that produce less dramatic platoon splits. On the whole though, throwing more sinkers to same-handed hitters and avoiding throwing them to opposite-handed hitters is probably a good adjustment for most pitchers to make, and is certainly a strategy that the Rays have bet on in recent years.

Which pitchers are not doing this?

This stark disparity in results and usage poses the question, are there pitchers in baseball who are doing this “all wrong?” What I mean by that is, are there pitchers who throw more sinkers to opposite-handed hitters than same-handed hitters? It turns out the answer is yes.

None of the Rays pitchers mix their sinkers in this reverse way, but there are quite a few arms from other teams who do. The table below shows the ten pitchers in baseball who had the largest R/L sinker usage difference, but in the completely opposite way that was shown before. If these pitchers were to reverse this trend, how good could they become?

For some reason, these pitchers are throwing a higher proportion of sinkers to opposite-handed hitters. It’s an interesting list, and some of these pitchers might have good reasons for doing what they do — if you had Sergio Romo’s slider, would you throw righties anything else? But I can’t help but think there is improvement opportunity in some of these arms if they were to flip this pattern. For instance, Irvin has posted a reverse wOBA split in his career — would more sinker to lefties help him normalize that split by improving his results against same-handers?

Might another team target some of these pitchers and give them a new sinker attack plan? I would explore it, as there may be some untapped potential in these pitchers. Another interesting point here is that this list is littered with Oakland A’s (Irvin, Chafin, Montas, Trivino), a team who is rumored to be looking to sell off pieces once the off-season resumes.

Jennifer Buchanan-USA TODAY Sports

Conclusion

The Rays are always tinkering with new pitching strategies, and the case here is no different. While “throw your sinker to same-handed hitters” is not a revolutionary concept, it’s interesting to see Tampa Bay stress the philosophy to an extreme level.

I will be watching to see if the Rays make any pitch usage tweaks to their two newest arms in Brooks Raley and Corey Kluber. There is a lot to like about both pitcher’s arsenals as they sit today, but the Rays are always looking for even the smallest of advantages, and maybe they see opportunity in those guys.

Yonny Chirinos is another sinker-heavy Rays arm who we haven’t seen pitch since August 2020, but hopefully his rehab from Tommy John surgery goes well and he’ll be able to return in the second-half of 2022. His sinker usage was trending in this exact way (more sinkers to righties, less to lefties) in 2020 before he got hurt, I’d expect to see more of that from him this season.

I’ll also be on the lookout for any minor league pitching signings that fit into the Aaron Slegers/Chris Mazza mold. The Rays will have roster spots to play with in spring training (which is when currently injured players will be eligible for the 60-day IL) and have a recent history of bringing in a flurry of pitchers from outside the organization around that time.

How do the Rays churn out consistently great pitching staffs despite relying on significant contributions from lesser known players? By finding small efficiencies like this and then weaving them through their scouting, training, and game planning, to identify players who do something well and then asking them to use that ability to its greatest effect. It’s these small advantages that can make the difference over the long haul.