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How spin led the Twins out of the pitching wilderness - Part 3

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Developing active spin and emphasizing tunneling are the final pieces of the puzzle

Minnesota Twins v Chicago White Sox Photo by Quinn Harris/Getty Images

This is the final part of my deep dive into how Minnesota has improved it’s pitching by utilizing how pitches spin to their maximum advantage. In part 1, I showed how the club has emphasized breaking balls (especially sliders) and minimized fastballs. In part 2, I showed how they made adjustments to the fastballs they did throw. Those adjustments included throwing far fewer sinking fastballs and improving fastball locations to throw elevated four-seamers higher up in and above the strike zone and sinkers down and below it.

As a result, Twins pitching has gone from one of the worst units in baseball to one of the best in just four seasons. The past two seasons Minnesota pitchers have collectively ranked 3rd and 2nd in Fangraphs’ version of WAR. Combining the two seasons, the Twins rank 1st in fWAR, 4th in FIP, and 7th in ERA. In 2020, the club pulled off the rare double feat of having baseball’s most valuable sliders and most valuable curveballs and it’s fastballs have yielded a batter line that is almost identical to the league average batter production against fastballs over the past four years, after previously being some of the worst in the sport.

In addition to using spin data to implement a heavy use of breaking balls and more optimal use of fastballs, there are two other spin related improvements that have contributed to this dramatic pitching modernization. Maximizing active spin and deploying pitches to take advantage of the effects of tunneling are the final pieces of the puzzle of Minnesota’s turnaround on the mound.

Spin Rate, Velocity, and the Twins

One of the constant prominent stories in the six MLB seasons since Statcast was implemented in all Major League Stadiums before the 2015 season has been high velocity fastballs with high spin rates.

As I discussed in depth in Part 2, the data is clear that there are positive relationships between velocity and spin rate and also between spin rate and batters swinging and missing. Said more simply, higher velocity fastballs tend to have higher spin rates and fastballs with higher spin rates tend to get more swings and misses (even at the same velocity).

As a result, teams have aggressively sought to acquire pitchers with high spin rates and high velocity which has made the market for pitchers with these unique characteristics very competitive and expensive.

This emphasis on spin rate appears to play out in league wide data. The average spin rate for MLB four-seam fastballs has increased year over year in five of the last six seasons and each of the last four. The overall change from 2016 is just slightly more than 3% (from 2238 RPM to 2306 RPM). While that’s not a dramatic difference, the consistent year over year trend seems telling. Similarly, the average spin rate on curveballs has increased every season of the Statcast era, jumping a combined 9.9% since 2015 (2304 RPM to 2532 RPM).

This is also happening when the average MLB fastball velocity has increased year over year, almost without pause, for the last twenty years (as I showed in Part 1).

Interestingly, though, Minnesota doesn’t seem to be one of the leading clubs in these areas.

At the club level, Minnesota has consistently ranked among the very bottom teams in four-seam fastball spin rate in recent years. The Twins 2243 RPM average four-seam fastball spin rate ranked 18th in 2017, the highest ranking of the Falvey era. In the three seasons since, Twins four-seamers ranked 25th, 30th, and 25th in spin rate. Minnesota ranked 10th in curveball spin rate in Falvey’s first season, but has been in the bottom half each of the last three seasons — 17th, 24th, and 16th respectively.

Minnesota also has not seen a dramatic change in overall fastball velocity. Ranking in the bottom third of the 30 MLB teams in fastball velocity was a hallmark of the Terry Ryan era and it has largely continued to be true in the four seasons under Falvey.

Only in 2019 did Minnesota’s average fastball speed (93.1 mph) crack the top half of MLB, and that was the first time since 2010 the team had done so. In the three other most recent seasons the team averaged about 92 mph and ranked 30th, 21st, and 29th.

That isn’t to say the Twins don’t care about velocity or spin rate or that they haven’t tried to prioritize those characteristics in acquiring and developing players.

They have.

But as is always the case for this franchise, their market position hasn’t allowed them to play at the top of the market where the high-velocity, high-spin rate combination resides. Instead, they’ve found value in less obvious places, like adding veteran pitchers that work at lower velocities with high spin rates like Rich Hill, Tyler Clippard, and Caleb Thielbar. They’ve also targeted these characteristics in trades to acquire prospects — including Jorge Alcala, Jhoan Duran, and Devin Smeltzer.

What Minnesota lacks in velocity and spin rate, they’ve more than made up for by turning the spin they do have into movement.

Active spin, in brief

While a lot of attention has been paid to spin rates, the raw rate of spin is only part of the equation. We mostly care about spin rate because of the relationship spin has with movement — and movement is ultimately what pitchers want. Other variables like arm slot, grip, and how a pitcher releases the ball also come into play, but pitch movement is driven mostly by spin.

Like any other skill, some pitchers are better at turning their spin into movement than others. Thanks to the detailed measurements made by Statcast we have the data and stats to prove it.

I’ll spare you from the detailed physics lesson and just summarize the key points you need to know about active spin (also sometimes called spin efficiency) and why it matters.

Thanks to the great work of University of Illinois Physics Professor Emeritus Dr. Allan Nathan we understand there are two types of spin for a thrown baseball — 1) “transverse spin,” and 2) “gyrospin.”

In part 2 I briefly explained that Magnus force is largely responsible for the amount of curve or ‘break’ a spinning baseball experiences as it is traveling to the catcher. Here is a quick and straightforward overview of how Magnus force impacts a thrown pitch. Dr. Nathan notes Magnus force is only sensitive to transverse spin. Gyrospin does not contribute to Magnus force at all.

What this means is gyrospin is not helpful for generating movement beyond that created by gravity and transverse spin is helpful for generating movement. Transverse spin is what a pitcher wants on their pitches and more transverse spin creates more movement.

To explain with an example, think of a football pass. A tight spiral is thrown with all gyrospin and no tranverse spin. The physics of a ball thrown with gyrospin keep the ball on a straight-line path to the target without movement (besides that caused by gravity). A football spiral doesn’t have a sharp break like a slider or curveball because of the lack of transverse spin. The lack of transverse spin on the football is because the spin axis of the ball is aligned with the direction of flight.

In contrast, think of a 12-6 curveball. This pitch is thrown with a lot of transverse spin (in this case, top spin) and very little gyrospin. Those physics result in sharp downward movement as the top spin works with gravity on a spin axis that is perpendicular to the direction of flight.

These two ideas might not be the easiest to digest. If seeing them written out isn’t working for you, check out this short video which does a good job animating the ideas.

OK, physics lesson over.

The point of making you slog through that was, thanks to Statcast (and other tracking technology like Rapsodo) and some mathematical equations not included here, the amount of transverse spin a pitcher has on any given pitch can be inferred and tracked. Active spin is the stat that measures how much of a pitch’s total spin is transverse, (i.e., how well a pitcher turns their spin into movement).

In practice, this is another data point for coaches and pitchers to work with to try to get the maximum out of a pitcher’s raw stuff. It’s also what the Twins have used to put together a successful pitching staff in spite of their lack of traditionally impressive “stuff”. The data is clear that Minnesota has some of baseball’s most active spinning pitches, especially since Wes Johnson became the pitching coach.

The Twins and active spin

The Athletic’s Eno Sarris wrote an article in August (subscription required) that included a 2020 team leader board for highest percentage of active spin on fastballs as measured by Statcast. It showed the Twins ranked 5th-best at 88%. My analysis of the end of season data came out to 87.9% for the Twins and ranked them 7th-best. Other clubs within the top 8 of this metric included many of the most advanced analytic-driven teams, like the Dodgers, Rays, Padres, Athletics, and Cleveland.

Unsurprisingly given the overall team ranking, there are numerous Twins ranked high on the Statcast active spin leaderboard for fastballs. Taylor Rogers (95.5%), Tyler Clippard (94.1%), Rich Hill (93.9%), Jake Odorizzi (93.4%), and José Berríos (92.7%) all showed up in the top quartile in 2020.

The same is true for Twins’ breaking balls. In 2020, their curveballs (78%) and sliders (43%) each ranked 4th-best in active spin and those leaderboards are littered with Twins. A quick caveat — sliders typically have a much larger component of gyrospin due to grip and release mechanics of throwing the pitch, which explains the comparably lower active spin figure.

Lefty curveballers Rich Hill and Caleb Thielbar are two of only seven major league hurlers who had 100% active spin. Lewis Thorpe (90.3%) and Devin Smeltzer (83.9%) are also among the top 15% of all pitchers. Hill (100%) and Thielbar (69.1%) also showed up among the leaders for sliders, as did Sergio Romo (73.6%), Taylor Rogers (61.3%), Matt Wisler (54.1%), and Cody Stashak (48.6%).

These numbers help explain how a pitching staff that possesses seemingly unimpressive raw characteristics like velocity and spin rate can become one of the most effective and valuable staffs in baseball. They also point to the idea that the Twins are exploiting an undervalued characteristic in acquiring and developing players.

Developing active spin

Unlike raw fastball spin rate, for which we have yet to find a natural, reliable way to increase, active spin is something that can be coached and improved.

The data provided by the high-tech tracking systems give players and coaches ways to conduct experiments — tweaking grips, arm slots, release points, and finger pressures — to maximize the active spin on a pitcher’s offerings. This, coupled with Wes Johnson’s penchant for coaxing additional velocity out of pitchers through mechanical adjustments, has helped Twins’ hurlers reach a higher level.

Jake Odorizzi is one great example. Acquired from the Rays prior to the 2018 season, Odorizzi had an up and down campaign in his first go around with Minnesota, pitching to 4.49 ERA / 4.20 FIP, striking out 22 % of the batters he faced and allowing 1.10 home runs per nine innings. That was his second straight season with an ERA above 4.00 and his fastball averaged below 92 mph. Thanks to a new off-season training program endorsed by Johnson and the Twins technology and analytic infrastructure, Odorizzi averaged 93 mph in 2019 on the way to a 3.51 ERA / 3.36 FIP, 4.3 fWAR, and a 27% strikeout rate. The last three figures were all career-bests.

But the velocity increase isn’t the whole story. Even with the velocity jump, Odorizzi’s heater speed was still well below average (23rd percentile) as was the pitch’s spin rate (39th percentile). Nonetheless, Odorizzi threw a bunch of fastballs (57.9% of his pitches), mostly up in the strike zone:

A location heat map like this for a seemingly below average fastball probably would make many pitchers and pitching coaches cringe. But, for Odorizzi it worked beautifully. His fastball allowed batters just a .209 batting average, .287 wOBA, and generated a whiff more than 30% of the time.

As you might guess by now, a key factor that made this success possible is a lot of active spin. In addition to the velocity jump, Odorizzi also improved his active spin from its 2018 levels. That season he ranked in the 75th percentile with 89.2% active spin (still good). But in 2020, he was able to improve to the 86th percentile with 91.4%. While those improvements might seem small, the margins in the highest level of baseball in the world are small, and they were enough for Travis Sawchik of Fangraphs to declare Odorizzi’s the best fastball of 2019.

Taylor Rogers and José Berríos are also worth noting, too. Like Odorizzi, they both rank quite low in overall spin rate on their fastballs — 19th and 25th percentiles respectively. However, as shown above, they both rank quite highly in active spin, indicating that they are getting the most out of their fastballs.

Developing active spin isn’t limited to fastballs. Thielbar’s storybook return to the majors last season was driven in large part by optimizing the active spin on his curveball, as he told Fangraphs’ David Laurila in October:

Laurila: So your curveball has gotten better…

Thielbar: “Yes.”

Laurila: Exactly why, and how, did that happen?

Thielbar: “Honestly, it’s pretty low-hanging fruit. It was just looking on Rapsodo and trying to improve the spin inefficiency of it, and therefore the break. I mean, I’ve always had the big 12-6 curveball, and it’s always been basically the same speed no matter how hard I throw. But after I saw it on a Rapsodo for the first time, it was like, ‘OK, now we can actually quantify things’ — we could look at it and see if it’s possible to make it better.

“It was a matter of manipulating my hand just a little bit better, and being able to get completely on top of it, to get close to 100% spin efficiency rather than 80%. That’s a pretty big difference, break-wise, and you just don’t see it with the naked eye. So there wasn’t anything super crazy. It was basically trying to improve on a pitch that was actually pretty good already. It wasn’t that hard for me to do, honestly. Being a high-arm-slot guy, it’s a little bit easier to get on top of a curveball than it maybe is for some other guys.”

While the 2020 season offered a small sample (just 20 innings) for the 33-year old former 18th round draft choice, Thielbar didn’t allow a single hit against his highly spin efficient curveball and the pitch got a whiff 38.7% of the time he threw it. Not only is it effective, it’s also the type of big, beautiful breaking ball that is frequently romanticized in baseball literature:

Tunneling for deception

Not only can the data provided by the tracking systems give players and coaches ways to increase spin efficiency, but it also can be leveraged to more effectively pair and sequence pitches together.

The physical realities of how incredibly difficult it is to hit a major league pitch are what makes this effective.

A pitch thrown 100 mph takes about 375 milliseconds to reach home plate after it leaves the pitchers hand. That’s literally “the blink of an eye” when you consider it takes between 300-400 milliseconds to blink.

Neuroscience research estimates that it takes about 100 milliseconds for the hitters’ brain to identify the ball and another 150 milliseconds or so to perform a swing of the bat. Some quick math means that leaves the batter only about 125-150 milliseconds to process the pitch trajectory and decide to swing or not, as this excellent video from Business Insider illustrates:

Research by Harry Pavlidis, Johnathon Judge, and Jeff Long at Baseball Prospectus identified a batter must make this decision and start their swing when the pitch is about 24 feet from home plate — a point they have named the “tunnel point.” From that point on, the hitter’s brain must extrapolate the pitch’s trajectory and make an educated guess as to where the pitch will end up.

For the pitcher then, you can see how it pays to throw pitches that move more than the batter expects after the tunnel point — the key reason why high spin rates and active spin percentages are effective for pitchers. Batters are essentially swinging blind the final 20 plus feet. Any deviations from the batter’s most likely expected trajectory for the pitch is to the pitcher’s advantage and the margins are small — just a few centimeters is enough to disrupt hard contact or getting a swing and miss.

Beyond subtle movements due to spin, it also pays for the pitcher to try to make all their pitches look the same at the tunnel point, a concept creatively called “tunneling.”

Let’s use a visual of Kenta Maeda to illustrate what I’m writing about:

See how Maeda’s different pitches are all in similar spots at the tunnel point before breaking all kinds of different directions? This deception is the foundational thinking behind tunneling and it’s gaining popularity across the game.

Minnesota is no exception. I’ve focused a lot on Tyler Duffey and his improvement in this series. Switching to primarily four-seam fastballs thrown up in the zone and complementing them with a lot more curveballs were the key adjustments he made to break out in 2019. But those adjustments were not two independent changes. They were made intentionally together to enable Duffey to tunnel those two pitches off one another more effectively, as he said late in the 2019 season:

“We all have our strengths and weaknesses and we’ve made it a point to capitalize on those strengths. I’ve gone pretty much strictly to four-seams, which has created a lot of useful movement that plays up in the zone. Being able to throw fastballs in that spot has made my curveball play up.”

For Duffey, the two pitches enhanced each other when he raised his sights on the fastball. Elevating it made it look more like his curveball out of his hand and the two pitches tunneled together longer. By the time the hitter had to make their decision, they wouldn’t be able to tell as easily if it was going to be 94 at their chest or a low 80s breaker below their knees. The change has completely changed Duffey’s performance and career outlook.

But high fastball-low curveball is not the only combination of pitches that tunneling can help.

Michael Pineda is a perfect example. Standing 6’7 and weighing 280 lbs, Big Mike is an imposing presence on the mound who largely pitches with stuff that isn’t intimidating in traditional ways. His fastball velocity is below average (37th percentile), it has one of the lowest spin rates in the game (3rd percentile), and it’s active spin (80%) is in the lowest quartile as well.

What Pineda does have, though, is excellent command and two offspeed pitches (slider, changeup) that tunnel incredibly well with his fastball, as this overlay by Michael Augustine shows:

Pineda has utilized this subtle skill to overcome his “stuff” to be a valuable mid-rotation starter for the Twins the past two seasons. Over 172.2 innings Pineda has delivered 3.91 ERA / 3.74 FIP and held opposing batters to a .252 / .292 / .411 line that works out to just .296 wOBA.

Regardless of the pitcher’s arsenal, Wes Johnson and the Twins pitching staff have taken to tunneling, as these fun overlays from Rob Friedman (@PitchingNinja) make clear:


At the end of part 2, I included a quote attributed to Hall of Fame pitcher Warren Spahn. He said, “Hitting is timing. Pitching is upsetting timing.” I think we often lose sight of this simple perspective in our quest to obtain power pitching. Of course, there will always be a place for power pitching in baseball and it may always remain the preferred way to build a winning pitching staff. But it’s not the only way.

Teams in the market position of Minnesota have to be realistic about where they can compete and open-minded about where they might find advantages. When you consider the physical difficulties of a batter hitting a major league pitch, it becomes clearer that the advantages to be found don’t have to be huge. An extra percent of deception, centimeter of movement, or mile per hour, here and there can really add up to upset hitter timing.

The collective adjustments I’ve highlighted in this series — throwing more breaking balls, more optimal fastball usage and location, increased active spin, and tunneling — are the marginal improvements that have helped the Twins overhaul their pitching philosophy and performance the past four years.

After years of being behind the times and ineffectively focused on outdated pitching adages (like working down in the zone to coax early contact), Twins pitchers have finally been given the tools to identify their individual best stuff, understand it and how to use it, and then encouraged to do that as much as possible.

True to Falvey’s stated intent for the organization, Minnesota has found success democratizing data and staying on the cutting edge of technology to identify and develop players’ individual strengths. Identifying and exploiting these small advantages is the competitive frontier the Twins are facing now and in the future. For a mid-market franchise, it’s a smart approach that makes the most of what they have and allows them to consistently find hidden value.

The game will continue to evolve. While nothing is guaranteed in the future, the returns of the last four years and the approach that generated them should make us all feel good that the Twins seem positioned well to evolve with it.

(Data throughout this post was sourced from Fangraphs.com and baseballsavant.mlb.com)


John is a contributor to Twinkie Town with an emphasis on analytics. He is a lifelong Twins fan and former college pitcher. You can follow him on Twitter @JohnFoley_21.