With spring training in the books and as we begin to forget its many forgettable performances, I recently thought about what I’ll take away from the games I watched. For me, the highlight was getting to see Marcus Stroman pitch to major league hitters. I was blown away by a lot of things—his fastball command, the ease of his delivery, and his consistent release, to name a few—but I was most impressed by Stroman’s stuff and his ability to miss bats.

The 5-foot-9 right-hander might be a little bit vertically challenged, but he has all the makings of a front-line starter. His plus-plus slider is a deadly pitch, and it comes out of the same arm slot as his fastball. The pitch shows remarkable depth, and it wouldn’t be hard to confuse the offering with a curveball. It can act as a put-away pitch when he throws it in the dirt, but he also can throw it over the plate when he’s behind in the count and needs a called strike.

Stroman hardly has needed to make use of his change-up in the low minors, but it’s not too shabby, either. He’s able to throw it about 10 mph slower than his fastball without slowing down his arm much, making it an extremely deceptive pitch. On top of the speed differential, the pitch shows some arm-side movement.

And the fastball. To the naked eye, Stroman’s fastball is electric. It seems to explode out of his hand, and it looks anything but flat as it makes its way to the plate. I knew it wasn’t really a sinker, but I wasn’t quite sure what to call that thing.

Others who were able to see Stroman pitch in March may think I’m crazy for extolling his repertoire. After a great 2013 season with Double-A New Hampshire, a few nasty spring training hiccups prevented him from breaking camp with the Jays. In his last 2014 major league spring training appearance, he recorded one out (on a pickoff play) and allowed seven earned runs.

In an effort to prove something to the Stroman skeptics out there and to find a comparable for Stroman’s fastball, I did what any geek would do—I went to Brooks Baseball to look up some numbers. But before I get to those numbers, let me talk a bit about pitch spin and introduce two types of fastballs you should be familiar with.

What Is Spin Deflection, and Why Should I Care About It?

Sportvision’s PITCHf/x system has allowed us to quantify certain aspects of a pitcher’s “stuff” that we used to be able to measure with only our eyes. We’re used to looking at radar gun readings, but we all know there’s more to a fastball than its velocity. If we want to know a little more about what a fastball does after it leaves a pitcher’s hand, we can look at a few other numbers.

Spin deflection, according to former THT Analyst Mike Fast, is the “deflection of the ball due to the spin force” the pitcher exerts on it. If that definition doesn’t do it for you, try replacing “deflection” with “deviation from a straight-line path.”

Measured in inches, spin deflection values are closely correlated with actual, real life, pitch movement (if you ignore things like gravity and drag). Overall spin deflection can be separated into horizontal and vertical components, each of which is measured by PITCHf/x cameras. These values, when taken together, help us classify pitch types better than perhaps any other single piece of the PITCHf/x smorgasbord.

So, that’s spin deflection in a nutshell. Now let’s use it to describe a few types of fastballs we know and love.

The Riser

A fastball thrown with a lot of vertical spin deflection appears to rise as it reaches the plate. (In reality, a “rising” fastball falls—it just sinks at a slower rate than the average fastball.) Fastballs thrown with a lot of backspin will register large positive vertical spin deflection numbers. Exceptional risers (like the one on display below) register somewhere between nine and 11 inches of vertical spin deflection.

Wandy Rodriguez’s 89 mph heater is one of my favorite examples of a rising fastball. It (sometimes) fools hitters into swinging through the pitch, and it can be especially effective when thrown up in the zone. Slow, rising fastballs can beat even the quickest of major league bats.

Unless you’re standing in the batter’s box, it’s easy to overlook a rising fastball. The centerfield camera angle that we watch most games from makes vertical spin a tough thing to spot.

A Hardball Times Update by Rachael McDaniel Goodbye for now.

Risers tend to generate a lot of swinging strikes, fly balls, and foul balls. Koji Uehara’s plays well with his diving splitter, and he became well acquainted with these three outcomes throughout the 2013 season as he developed one of the league’s best fastballs. Trevor Hoffman used to throw a fastball with similar movement, but if you’re looking for more current examples, check out hurlers Chris Tillman and Tim Lincecum.

Major league teams are well aware of the batted-ball profile that accompanies a rising fastball. In an interview with FanGraphs’ David Laurila, Colorado Rockies senior vice president of major league operations Bill Geivett discussed the team’s player acquisition strategy. He recognized the effect of fastball spin on batted-ball types and stated that he shies away from bringing rising fastballs to Coors Field:

Straighter fastballs… typically, those are flyball pitches. Those type of guys, unless they can adjust their game, are probably not a true fit for us.”

The Runner

The type of pitch I just described (a fastball thrown with a ton of vertical spin and little horizontal spin) isn’t very common across the major leagues. A much larger group of pitchers throws what I like to call “runners” (fastballs with exceptional horizontal spin). These pitches, often thrown with two-seam fastball grips, move laterally and also tend to sink at a quicker rate than the average fastball. (Note: traditional sinkers also fit into this category.)

The horizontal spin produced by a two-seam fastball or a sinker causes the ball to move laterally at a quicker rate than the average fastball. Runners typically have much less vertical spin deflection than a riser (sometimes as small as two or three inches) but a lot more horizontal spin deflection. Exceptional runners register anywhere from nine to 12 inches of horizontal spin deflection. The movement generated by this pitch tends to induce tons of groundballs and called strikes on the corners of the strike zone.

Here’s a great example of a running fastball:

Bartolo Colon resurrected his career with this pitch. Almost nine out of every 10 pitches his genetically modified arm releases are running fastballs, and according to FanGraphs’ linear weights values, these fastballs fare better than the league average. Chris Sale also throws a pretty good runner, and Hisashi Iwakuma’s isn’t bad, either.

Why Spin It?

There are clear benefits to both types of spin. The graphs below (which appear in my article in the 2014 Hardball Times Annual) plot horizontal spin and vertical spin against average pitch outcomes for over 1.5 million fastballs thrown over the last three years. Negative values represent good outcomes for the pitcher (swinging strikes, outs, etc.), and positive values represent bad pitcher outcomes.

A short excerpt from the article highlights the importance of spin:

With one caveat, pitchers allow fewer runs on fastballs with more spin deflection. In fact, a two-inch increase in horizontal (or vertical spin) appears to have roughly the same effect on results as a two-mile per hour increase in velocity. True, we can’t look at these results in a vacuum—but it is clear that spin deflection matters.

In case you’re wondering, that caveat pertains to sinkers. Pitchers like Justin Masterson and Trevor Cahill benefit from a lack of vertical spin, which makes their sinking fastballs tougher to square up. When sinkers take on vertical spin, they don’t sink as much. Sinkerballers love ground balls, but they love gravity even more.

If we set those who throw hard sinkers aside, we can say that we like to see more of each kind of spin deflection.

Putting the Two Types Together

This brings us to Stroman. Unless you’ve seen him pitch in person, it might be hard to come up with a good comparison for Stroman’s fastball. He’s right handed, and he generates arm-side movement (toward right-handed hitters) on his fastball. There are a ton of pitchers that meet this basic profile. Some are great, and some are pretty unexceptional, so what makes Stroman different?

Well, for one, he throws his fastball 93-95-plus mph. If he can maintain that velocity throughout a start, he’ll find himself with pretty strong company in the big leagues.

But Stroman doesn’t just have velocity. He’s also got the good spin, and he has two different brands of it. See if you can spot it in these clips. In each one, try to pay attention to how the hitter reacts; a hitter’s reaction usually tells us more about a pitch than our eyes do.

In this first one, the hitter does a little shimmy away from the plate—almost as if he thinks he’s going to get hit by the pitch. This isn’t an uncommon reaction from a left-handed hitter to a Stroman fastball.

The second clip comes from a recent minor league spring training game. The catcher sets up on the outside corner, but the pitch darts back over the plate ten minutes after the hitter gives up on it. It’s horizontal spin in action.

The last clip (which comes from Stroman’s college days at Duke) is the result of strong horizontal and vertical spin. While the horizontal movement is obvious, the vertical movement may be tougher to spot (especially from this camera angle).

I mentioned before that I clicked over to Brooks Baseball as soon as I saw Stroman throw. I was relieved to find that PITCHf/x cameras have caught Stroman in action on three separate occasions (one outing from last March, one 19-pitch Arizona Fall League outing, and one two-pitch AFL outing).

Between these two “real” outings, Stroman has thrown 19 fastballs. We can thank Pitch Info for classifying these fastballs (and all other pitches PITCHf/x tracks) by hand. Is 19 fastballs enough to project Stroman? Probably not, but I can’t help but get excited about what I saw.

Stroman’s fastball has averaged around 9.1 inches of arm-side spin deflection and 9.9 inches of vertical spin deflection across these two outings. It is encouraging to see consistency in each reading dating back to last March, and it is also encouraging to see that other major league pitchers who threw in that 2013 spring training game registered numbers that were in line with the rest of their 2013 outings. Otherwise, I’d be inclined to think that the cameras were a little off that day.

Comparables

The cameras agree; in terms of movement and velocity, Stroman’s fastball is anything but average. If we were to compare Stroman’s fastball to that of a current major leaguer, who would our candidates be?

In the table below, I pulled all fastballs thrown by major league pitchers that match up (in terms of speed and spin) with the Stroman fastballs that PITCHf/x has logged. I’m creating a rough comparison here based on a few factors (speed and spin deflection). I only looked at right-handed pitchers (because we’re looking for arm-side movement). I used the following criteria to create matches:

velocity within +/- 1.0 mph of Stroman’s average (93.93 mph)

horizontal and vertical spin deflection within +/- 1.0 inch of Stroman’s averages.

The top 25:

Did you expect to see Ernesto Frieri at the top of the list? I sure didn’t. Should Stroman wind up in the Jays’ bullpen, Frieri is perhaps a great comparison. Frieri throws a fastball that looks a lot like Stroman’s, and he has a mid-80s slider to boot.

Stroman may have an approach that is a little more polished and delivery that is a little more consistent, but the raw “stuff” looks very similar. I think most young pitchers would love to hear that their fastball projects to challenge hitters as much as Frieri’s does. The Angels’ closer throws his fastball almost exclusively, and he generates tons of outs with it.

A GIF is worth at least a few more words. Frieri’s rising, running heater:

Stroman’s fastball also resembles 170 or so thrown by pair of Detroit Tigers starters you may have heard of. Justin Verlander and Max Scherzer throw a little bit harder than Stroman does, and that may be why we don’t see more of their fastballs showing up on this list. Lance Lynn and Shelby Miller, each of whom dominated hitters with fastballs last season, also make the list.

Starters throw more than three times as many pitches as relievers do over the course of a season, yet some elite closers have thrown more comparable fastballs over this period than many starters have. So, when we see that Frieri has thrown more comparable fastballs than any other pitcher (starter or reliever), his 127 fastballs gain even more weight. Does this mean Stroman is heading for the bullpen? Not necessarily. His fastball is certainly as lively as a closer’s, though, and that can only mean good things.

Hold on, though. In this grab bag of fastballs, we don’t see only elite pitchers. We also get some Jeremy Guthrie, some Jason Hammel, and some Jake Arrieta. Maybe Stroman’s fastball projects to fall within this unexceptional group.

We could keep trying to find one pitcher whose fastball most closely matches Stroman’s, or we could project Stroman by digging up every pitch thrown that matches the velocity and spin deflection levels we’ve seen from him.

So, if some of Verlander’s fastballs look like Stroman’s, and some of David Hernandez’s do too, then I’ll take all of those fastballs (which were also used to generate the list above) and group them together. This group of 2739 pitches can be used to form a loose projection of how Stroman’s fastball might fare in the big leagues.

How Successful Are “Stroman” Fastballs? Pitch Outcome Rate Swing % 42.0% Misses/Swing 19.8% Ball in Play % 16.4% Home Run % 3.6% Groundout/Flyout ratio 0.90

Since we’re only looking at three factors, we can’t say that we’re getting a complete measure of pitch effectiveness here. We are temporarily forgetting how the pitch is released, it’s location, game context, and everything else that makes a pitch “work.” By these numbers, pitchers who lack fastball velocity shouldn’t be effective—but a deceptive delivery, plus command, or a long stride can turn 89 mph into a misleading number.

That said, this group of comparable fastballs has generated some special results. On the whole, these fastballs have caused hitters to whiff on one out of every five swings. That’s more than double the league-average swinging strike rate for all pitches, and it approaches Cy Young winner Scherzer’s 2013 fastball whiff rate (23.28 percent). These fastballs were hit in play at a little more often than Scherzer’s or Verlander’s were last season, and they didn’t leave the yard too often.

It is also interesting that this type of fastball doesn’t necessarily match a heavy groundball profile. Stroman posted a 1.15 GO/AO ratio in 2013, so he wasn’t too far off from this group. If he works to hone the natural tailing action his fastball gets, Stroman could develop a running fastball that would push this ratio higher.

What About Archie Bradley and Yordano Ventura?

Okay, so maybe Stroman’s fastball won’t be the best to hit the big leagues this year. On Tuesday night, Yordano Ventura hit levels of movement and velocity that we have yet to see from any other pitcher in the PITCHf/x era. Ventura’s fastball, which Baseball America grades as a “true 80 pitch” (on the 20-80 scale), featured the exceptional vertical spin deflection we attribute to a Koji Uehara.

The difference between Uehara’s fastball and Ventura’s? Ventura’s averaged over 99 mph on the gun and hit 102 mph twice. Ventura’s common fastball is actually similar to Aroldis Chapman’s. Ventura is especially exciting because he has also demonstrated the ability to create arm-side movement on the pitch without losing velocity. If you’re heading to the plate to face Ventura in the near future, look out for a 100+ mph rising fastball and the occasional 100 mph sinker.

There are also some other great young arms waiting for their shot under the PITCHf/x lights, too. There are a few fastballs in the minor leagues that have had scouts giddy for months, and hopefully we’ll see some of those pitchers debut at the major league level in 2014. Top prospect Jon Gray has already thrown a few “Stroman” fastballs in Arizona Fall League action, and we’ve yet to see what Bradley can do.

If nothing else, these comparisons and projections can entertain us until Stroman takes the mound in the big leagues. We may not see him in Toronto for a little while, but you can bet he’ll be fun to watch once he gets the call. Until then, I’ll be his biggest fan.

Note on PITCHf/x spin measurement:

If I had other pitch information to look at, like TrackMan’s spin rates, I might not be messing around with PITCHf/x spin deflection numbers. While PITCHf/x infers spin rates based on pitch movement, TrackMan measures both pitch movement and the actual spin causing it. Alan Nathan defines these two measures as “total spin” and “movement spin.”

We care about the effect of spin on pitch effectiveness, and it is possible that TrackMan’s “total spin” is more closely aligned with things we care about (swinging strikes, contact, etc.). If TrackMan were to make that data public (it won’t), we could compare the two. For now, I’ll work with what we do have.

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