Two Unheralded Acquisitions Could Bolster Bombers’ Postseason Bullpen

Since the dog days of summer, the Yankees’ bullpen has been dogged by injuries and ineffectiveness. It began with the losses of Michael King and Chad Green for the season. But those that shored up the ‘pen in their wake have since gone down as well.

Clay Holmes‘ shoulder issue and recent struggles have called into question just how much the team can rely on him come the playoffs. Surprisingly stellar rookie Ron Marinaccio exited his last regular-season game early due to a lingering shin injury and has been ruled out until at least the ALCS. This came on the heels of Zack Britton’s 60-day IL placement, as his late-season comeback attempt fell short. Stalwarts Wandy Peralta, Miguel Castro, and Albert Abreu are also either still injured or shaking off the rust. Not to mention the unceremonious end to the Aroldis Chapman saga: he was left off of the ALDS roster for missing a mandatory team workout on Sunday.

Thankfully for the Yankees, despite a disastrous trade deadline in which they ended up sacrificing 1.8 WAR, they did manage to acquire some bullpen reinforcements. Relievers tend to accumulate less WAR due to their lower volume of innings, downplaying the surface-level effectiveness and importance of lower-profile acquisitions Scott Effross and Lou Trivino. Their significance is only set to increase with the Yankees’ bullpen situation becoming increasingly dire. (Update: Unfortunately, shortly after this piece was published, Jack Curry of YES Network reported that Effross, who was absent from the Yankees’ ALDS roster when it was released on Tuesday, will need Tommy John surgery.)

The deal for Frankie Montas, who may not even pitch in the postseason, has hurt the Yankees and may continue to do so depending on the development of Ken Waldichuk, currently ranked 69th on The Board. But Trivino is doing his best to make up for it. Somewhat of a throw-in alongside Montas, he stumbled to a 6.47 ERA in the first half with the A’s. While his 2.88 SIERA signaled better days ahead, his 42.7% hard-hit rate and 9.4% barrel rate (versus league averages of 38.2% and 7.5%, respectively) indicated some cause for concern, maybe even somewhat justifying his astronomically high BABIP of .451 (!). Those worries have largely been quelled since: Trivino tossed 21.2 innings of 1.66 ERA ball with New York, and while his hard-hit rate remained high at 54.2%, his barrel rate (3.4%) and BABIP (.293) both came back down to Earth.

The divergence between Trivino’s hard-hit and barrel rates could be because balls classified as hard-hit by Statcast require only an exit velocity of 95 mph or higher, while barrels require an EV of at least 98 mph and a specific range of launch angles at each speed. Trivino still seemed to allow more balls in play at 98-plus with the Yankees, as you can tell by the blue line increasing more steeply below:

However, these hard-hit balls aren’t necessarily falling in the ideal 25–30-degree launch angle range like they were during his time with the A’s:

Outlined in red is a cluster of well-struck balls at optimal launch angles, one mostly consisting of Oakland green. Circled in gray is another cluster of balls, to the right of the first one and consisting almost entirely of New York navy, that represents well-struck balls that hitters got a bit under. While the proportion of Trivino’s fly balls that are infield popups decreased by 2.7%, his fly ball rate itself increased by 5.5%, largely at the expense of line drives.

What explains the change in batted-ball profile? Likely a change in pitch mix. The Yankees’ scant use of the four-seam fastball rubbed off on Trivino, as his usage of the pitch dropped 10.8% after he was dealt. On the season, his four-seamer allowed an exorbitant 40% line-drive rate; according to Statcast’s pitch values, with the A’s, the pitch cost him on average 4.2 runs per 100 tosses.

Trivino’s slider absorbed the bulk of the four-seamer’s utilization, more than doubling to a usage rate of 35.3%. It allowed a 13% line-drive rate on the season, helping him prevent 0.69 runs per 100 throws in his time with the A’s. And that number improved to 2.24 after he joined the Yankees, despite its increased usage. Trivino’s sinker, which became his primary fastball with the four-seamer sidelined, paired well with the slider, moving from costing 2.32 runs per 100 to preventing 0.58. Together, the sinker and slider represented 65.3% of the pitches he threw for the Yankees.

Though it’s a much smaller sample, for his part, Effross actually saw a five percent increase in four-seam usage after joining the Yankees, largely at his sinker’s expense. However, his four-seamer already prevented 1.5 runs per 100 before the trade; due to his unorthodox release point, it has top notch (99th percentile) horizontal and vertical movement among pitchers who threw at least 50 this year. Its velocity — just 90.8 mph — leaves something to be desired, but that mark still bested right-handed side-winding peers Tyler Rogers and Adam Cimber by 7.6 and 4.3 mph, respectively.

While his four-seam usage increased slightly during his time with the Yankees, like the New York version of Trivino, Effross relied heavily on a sinker-slider combo. On the season, the two offerings comprised 74.7% of his pitches (70.4% with the Yankees). His sinker finished in the 95th and 98th percentiles for horizontal and vertical movement; his slider, in the 81st and 75th.

Conventional wisdom holds that sinkers and sliders pair especially well together. If it weren’t for that, it would make sense for Effross to throw his four-seamer more, given its elite movement; it would make sense, too, for Trivino to ditch his sinker and its paltry drop.

Yet both pitchers also have above-average sliders that should be a part of their repertoires:

And what makes the decision even easier is that each sinker-slider combo represents an almost-perfect 165-degree spin-axis differential (180 degrees would be perfect):

This creates a spin-mirroring effect wherein the two pitches rotate about a very similar axis but actually spin and move in nearly opposite directions. Due to the similarity of their spin axes, those pitches are extremely hard for the batter to differentiate.

If you look closely, both pitchers also have a 165-degree spin-axis differential between their four-seamers and sliders. For Trivino, this shouldn’t matter, because his sinker generates 7.5 more inches of run than his four-seamer; if both pitches look like the slider, he should pair the sinker with it, since that offering moves much differently from the slider. For Effross, the answer isn’t so simple: his sinker only runs 0.6 inches more than his four-seamer on average, and the four-seamer is 0.5 mph harder. The Yankees may be experimenting to see if it’s worth using the four-seamer more at the sinker’s expense.

Otherwise, Effross was much better than Trivino before his own trade, so it makes sense that the Yankees didn’t enact more significant changes to his repertoire. And though they sacrificed late-season breakout Hayden Wesneski for Effross, it was easy to see why. In 44 innings with the Cubs before he was traded, the side-armer shut down the opposition to the tune of a 2.66/2.18/2.94 ERA/FIP/xFIP. Prior to missing a month with a shoulder injury, he had gotten off to a solid start with the Yankees, too, tossing 8.1 innings of 3.24 ERA ball. He threw 4.1 scoreless after returning, setting the stage for success in his first postseason.

With the ALDS looming, now is likely not the time to tinker further with arsenals. More fastball changes may be in Effross’ future, but he’s proven effective as is, and Trivino’s arsenal changes have had plenty of time to play out successfully. While they may have to answer for their prospect losses at the deadline for years to come, the Yankees might be able to enjoy a reprieve if Trivino and Effross can come through for the rest of October.