Tyler Duffey Is Trying Something New

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Tyler Duffey. You know him; you may like him! The Duffman is now the longest-tenured Twins pitcher, debuting in 2015 back when Ryan O’Rourke and Blaine Boyer were a thing (Caleb Thielbar was technically on that team also, but he took a bunch of years off, so it doesn’t count the same). Evolution has defined his entire career; Duffey moved to a relief role in 2019, cut his changeup, and found new success as a reliable late-inning arm. He’s back to tinkering in 2022.

2019 is the pivotal year in this discussion. Yes, those previous seasons do count, but Duffey was a different pitcher, so different that analyzing those years does not help us. The Twins front office decided that Duffey would not be up to snuff as a starter (probably true) and moved him to the bullpen where his fastball/curveball combo could play up. Friends, that’s exactly what it did. Duffey averaged 94 MPH with his fastball and spent 57 ⅔ innings laying waste to batters to the tune of a 2.50 ERA with great peripherals (3.06 FIP, 2.94 xFIP).

Success since that year has been inconsistent, though. He was better in 2020 (1.88 ERA, 2.57 FIP), but his peripherals fell off a cliff in 2021 (3.49 FIP, 4.19 xFIP, enough walks to start a protest). He became hittable and less deadly outside the strike zone, as both his O-Swing % dipped (33.9% in 2019 to 26.6% in 2021) and Contact % rose (69.2% in 2019 to 77.9% in 2021); a terrible combination for any pitcher. Oh, and he’s lost a tick and a half on his fastball.

The fastball is perhaps the most interesting pitch in Duffey’s repertoire. His curveball always had deep, visceral movement, the kind of drop that pushes one to theorize that all stadiums have a baseball magnet hidden underneath home plate. His 4-seam fastball, though, never carried great traits. It spins a bit more than average but doesn’t ride in the way that Justin Verlander’s heater can look like it’s elevating towards heaven. Still, he had enough juice to effectively attack hitters at the top of the zone in 2019. In the years since? It’s a different story.

That’s… something; he’s become unpredictable, which can help to a degree (the hitter can’t know where the pitch is going if you don’t either), but inconsistency has plagued him with this new strategy. His solution? Re-invite the sinker to the party.

He’s thrown the sinker 10.8% of the time—mainly against righties—and has successfully thrown it in exactly one location. See if you can spot the pattern:

The pitch has excellent Statcast outcomes, but with only six batted ball events against it, bringing up those numbers seems foolish. Overall, Duffey has had an inconsistent start to his season, more than what one would expect from any reliever. The good news is that he might be ahead of the curve by trying out his sinker more; the bad news is that it is unclear yet whether that plan will work. Either way, Duffey is a changed pitcher in 2022.