A pitcher’s swinging strike rate is one of the better measures of how well they are performing. It correlates well to their overall strikeout rate, and is one of the three gold standards I use (along with other methods) to evaluate a pitcher as a whole, in conjunction with O-Swing% (how often a hitter chases) and Z-Contact% (how little hitters make contact with pitches in the zone).

SwStr% can be used to inspect the effectiveness of either an entire arsenal or an individual pitch, and is a strong indicator of how good a pitcher’s “stuff” is. As such, an increased SwStr% is a desirable outcome for a pitcher. Obviously, some pitching styles don’t lend themselves to missing bats, and instead are good for timing disruption and/or weak contact.

One pitcher who fits the mold of a bat-misser is the young lefty prospect from the Oakland Athletics, Jesus Luzardo.

With a minuscule sample of just six games in 2019, amounting to 12 innings pitched, Luzardo had a strikeout rate of 34% (versus a 6.5% walk rate), and held hitters to a .119 batting average with an 0.67 WHIP while posting a 2.36 FIP (1.50 ERA). Luzardo was pretty good during the American League Wild Card game as well. Back in October against the Tampa Bay Rays, he pitched three innings, allowing one hit and two walks while striking out four. Read the rest of this entry »

Back in November, I wrote a piece on spin mirroring in which I broke down the phenomenon and its applications, along with theories on its effectiveness. There have been some misconceptions about how spin mirroring actually works. I’m going to attempt to break down how to create “true” (or parallel) spin mirroring, which is based on much more than just opposite spin directions. Spin direction, spin axis, tunneling, and “seeing” spin are all factors that make up this phenomena.

The premise of the strategy is based on a hitter’s potential to recognize spin and the pitcher having the ability to tunnel two pitches, which can create a repelling effect in terms of opposing Magnus force. This juxtaposing effect can create a large spread ratio between the tunnel point and the position of the pitches when they cross home plate. So long as the spin direction contrast is somewhere between 170 and 190-degrees, and their gyro degrees (where the spin axis is pointed in space) are similar, true spin mirroring can be facilitated.

The below example shows how spin direction and the spin axis of two pitches are affected by the contrary Magnus effect (as well as gravity), which creates the appearance of them almost pushing off from each other. There is no additional force from the balls themselves acting on each other; it’s simply how each pitch, individually, responds to this law of physics:

One thing I want to point out as we dive into this is that the Driveline EDGE tool I’ll be using doesn’t account for gravity, drag, or the effect seam orientation might have on ball flight, as well as any park factors like air pressure. These are provided to add visual context to reinforce my statements. That isn’t to say the tool doesn’t have uses otherwise; it relies more on the movement the pitcher is able to generate by himself, which is elaborated on here. Read the rest of this entry »

Curveballs can be fairly vexing to classify. Though not as vast as the kingdom of sliders, curveballs have more personality than other pitch types. Some curveballs have heavy sweep like a slider (slurve), or have a grip variation that will kill spin (knuckle curve); others can fall like a hard changeup (churve), while another variant seems to float in slow motion on the way to home (eephus).

Most tend to fit the more stereotypical slicing shape (sweep with comparable drop), or have a heavy arch that fits the 12-6 style. Each variation has its own identity and benefits depending on factors such as arm slot, spin direction, and axis orientation.

There are situations where a pitcher adopts a particular style but fails to execute the pitch, so it fits into its sub-category. You can have a 12-6 curveball that plots normally on the x-axis but fails to drop far enough down the y-axis. Or, you can have a more classic curveball that doesn’t separate itself enough from either plot point, which causes the pitch to hang in the zone.

But we can make adjustments to these undesirable results, and that’s what we’ll be focusing on in this piece. What can be done to add depth to a curveball that regularly demonstrates a lack of life or separation from the center of the pitch zone chart? Read the rest of this entry »

One area of potential weakness for the 2020 New York Mets is their bullpen. Even the seemingly strong backend of Seth Lugo, Dellin Betances, and Edwin Díaz leave more questions than answers. Lugo has been the most stable, but he may be competing for the fifth spot in the rotation. The Mets took a chance on Betances, who pitched in one game last season before going down again with a “freak injury” — what he’ll be capable of in 2020 is anyone’s guess. Díaz, whom the Mets traded for back in December 2018, and who was once one of the most dominant closers in baseball, ended up becoming a major liability for the bullpen.

The supporting cast of Brad Brach, Robert Gsellman, and Justin Wilson present some uncertainty as well. Brach pitched well after being released by the Chicago Cubs, but projects for less than a win. Gsellman is an average reliever, and Wilson is an injury concern after missing 10 weeks in 2019 with elbow soreness.

And if things do go south for the bullpen, the Mets’ reinforcements are limited. Among them is 29-year-old righty Paul Sewald, who might be an option in 2020, but there are some adjustments he’ll have to make before he can be a meaningful contributor. As it stands, Sewald may not even make the 2020 Opening day Roster. Sewald possesses good command of his three-pitch arsenal, which consists of an average four-seamer and changeup, with an above-average slider. Sewald mainly goes to the fastball and slider, with some changeup cameos from time to time:

Read the rest of this entry »

After an impressive 4.0 WAR season in 2019, 22-year-old right-hander Mike Soroka is set up to become the ace of the Atlanta Braves pitching staff. Soroka started all 29 games he appeared in last year and ranked 14th overall in FIP, with a 7.2 K/9 against a 2.1 BB/9 rate. Soroka induced grounders on over 50% of the contact he allowed, with a .206 GB BABIP (league average is .242 ). It’s a mixed bag of success when it comes to groundball pitchers, and Soroka ranked sixth overall in groundball rate last season (one spot behind his teammate Max Fried). Of the top 10 grounder rates in 2019, Soroka’s ERA was second to Hyun-Jin Ryu’s.

Soroka isn’t really a strikeout pitcher (142 strikeouts in 174.2 IP), but he does have a good mix of above-average pitches and velocity that keeps hitters wary. Soroka already does a pretty good job spreading out his arsenal, especially when ahead in the count and with hitters facing a two-strike count. Soroka’s repertoire has a few great pairing options, and if sequenced properly in the right game state, it could make the youngster dominant.

Let’s start by examining his arsenal. Soroka throws a two-seamer, a slurve, a four-seamer, and a firm, fading circle changeup. All four are demonstrated in the following isolated pitch overlay:

Read the rest of this entry »

Miami Marlins right-hander Sandy Alcantara showed a lot of promise when he was given a spot in the starting rotation last year. His 2.3 WAR and 3.88 ERA were impressive, but there’s much more going on that meets the eye. Alcantara has a very cohesive pitch ecosystem; the design of each offering makes for a lot of interchangeable parts. Being able to adapt to situations with flexible pitch options gives Alcantara an edge that a lot of pitchers don’t have with their arsenal.

Most pitchers have one, maybe two, pitch combinations that pair well together. Alcantara actually has four, which can allow him to easily flex and keep hitters on their toes.

Alcantara operates with five pitches: two fastballs (four-seam and sinker), a slider, a tight, classic curveball, and a heavy, fading changeup.

Below is the 2019 data on all five pitches: Read the rest of this entry »

The Arizona Diamondbacks have a potential future ace in 24-year-old righty Zac Gallen. Making his debut for the Miami Marlins in June 2019, Gallen finished the season with a 1.6 WAR, and armed with a filthy changeup, became one of the more exciting young pitchers to appear in the major leagues last year.

This spring, Gallen will battle for the fifth spot in the Diamondbacks rotation. If he isn’t able to secure a starting role, Arizona may have him begin the season in Triple-A. Gallen could claim that rotation spot with an assist from an adjustment to one pitch, which in turn will tighten up his entire arsenal and help him become one of the tougher pitchers to face in baseball.

Though the sample is limited, Gallen did well during his first 15 big league starts. Through 80 innings pitched, Gallen produced an ERA of 2.81 (3.61 FIP), struck out 96 hitters, and posted a 2.96 K/BB ratio. Gallen also demonstrated good command last year, though his 10.8% walk rate indicated he may have struggled a bit with his control.

Gallen attacked hitters with a four-seam fastball, a knuckle curveball, a changeup, and two types of cutters: a sweeping (or hybrid) cutter and a backspinning cutter. Eric Longenhagen put a 50 FV on Gallen’s overall arsenal, with special consideration given to his changeup (55 FV). Read the rest of this entry »

San Diego Padres right-hander Chris Paddack had a pretty good first major league season. He struck out 153 hitters in 140.2 innings and posted a 0.98 WHIP with a 3.33 ERA and a 3.95 FIP. Amazingly, he did it with basically two pitches: a four-seam fastball and a changeup. Paddack also has a curveball that he has often tinkered with, but its use never eclipsed 15% in any count. It mainly appeared as the first pitch of the at-bat or when he was ahead in the count. Despite being able to keep hitters under control with two options for most of last season, one of the multiple curveball variations Paddack resorted to works best, both statistically and as an ideal fit with his four-seam and changeup.

Here’s a visual summary of Paddack’s three pitches in an isolated overlay example, which accounts for the typical location of each pitch last season:

Paddack has a well-designed, pure backspinning four-seam fastball with a 12:50 spin direction and nearly 100% spin efficiency. In terms of whiffs, the pitch was best when Paddack kept it high in the zone. When it came to contact, the four-seamer didn’t really have an advantageous location, with the exception of keeping the pitch out of the middle of the strike zone. Paddack held hitters to a .276 wOBA and demonstrated good control of the pitch as evidenced by his 0.18 BB/K-rate. Read the rest of this entry »

Dan Szymborski recently posted the 2020 ZiPS projections for the Seattle Mariners. The system forecasts lefty Marco Gonzales to be the best pitcher on Seattle’s staff. That should come as no surprise considering that Gonzales has been far and away the best arm the Mariners have had to offer lately. According to ZiPS, he’s expected to throw at least 170 innings in 2020 and post a 4.26 ERA (4.12 FIP) with a WAR of 2.6. Despite his strong showings in 2018 and 2019, ZiPS indicates a fair amount of regression for Gonzales this coming season.

After two straight seasons of 3-plus WAR, can we expect a pitcher who throws two fastballs that barely reach 90 mph to maintain that level of performance? Despite his ability to spread his arsenal out, especially when he’s ahead of the hitter, there is a change to Gonzales’ pitch selection that could facilitate another impressive season for the 27-year-old former 19th-overall draft pick.

Gonzales threw five different pitches in 2019: a sinker, cutter, a fading changeup, a sweeping, slurve-ish curveball, and a four-seamer, all with above-average command:

As you can see, Gonzales throws three different fastball variations. His traditional cutter works just fine and by FIP, it was his best pitch in 2019. Its 11:40 spin direction facilitates little sweep but a decent amount of rise. Read the rest of this entry »

Free agent left-hander Robbie Erlin threw 55.1 innings across 37 appearances in a mediocre 2019 campaign. He gave up a lot of hard contact (43.7%), posted a 5.37 ERA, and saw his walk rate balloon to almost three free passes per nine innings. Erlin’s WHIP also skyrocketed from 1.14 in 2018 to 1.57 last year.

We can’t ignore that some bad luck may have found him; his BABIP was .373, almost 60 points higher than his career norm. That, coupled with the big jump in walk rate (2.7% to 6.0%), put Erlin in a lot of bad situations. Although he did manage to post a 3.61 FIP, that doesn’t sound like a pitcher destined for an especially promising 2020 season, if he’s picked up at all. So what value can be drawn from Erlin?

Well, for starters, Erlin mixes his pitches really well. The ability to keep hitters on their toes is advantageous regardless of how good your stuff is. In Erlin’s case, his stuff needs to be good, and there are ways in which he can make that happen.

Let’s first take a glance at Erlin’s five-pitch arsenal: a two- and four-seamer, a slider that is sometimes mistaken for a cutter, a curveball, and a changeup: Read the rest of this entry »