Mariners 2020 draft preview: LHP Reid Detmers

If you’re a Baseball America subscriber/follower (and we recommend it), you know that they’ve just completed a re-rank of the top high school players and top college players in the 2020 draft. If you’ve been following along with our draft preview series, most of the players in the top ten on each list should be familiar to you, especially with college, where longer track records mean more stability in the rankings. One player we haven’t gotten around to yet who has been consistently ranked in the college top ten is Louisville lefty Reid Detmers, so that changes today. FanGraphs has Detmers listed lower, at the 30th overall prospect and close to the 20th best college prospect, but MLB Pipeline also had Detmers in their list of top ten collegians way back in late August, calling him the “most polished arm in the 2020 crop.” A fast-moving college arm, you say? Sounds like Dipoto catnip to me.

Detmers was a well-regarded prospect coming out of the great state of Illinois, where he overmatched high school hitters with ease, striking out 153 batters his senior year, but with a fastball maxing out at 91 and a strong college commitment to Louisville, he went undrafted until a courtesy selection from Atlanta in the 32nd round. Detmers contributed immediately to the Cardinals, making 18 appearances and starting eight times his freshman year. While the high strikeout totals followed him from high school—in 55.2 innings he struck out 69 batters [obligatory “nice”]—Detmers struggled with his command, walking over 13% of batters. When he did put the ball in the zone, it proved a tasty treat for batters; Detmers surrendered nearly a hit an inning, with about half those going for doubles or homers, adding up to an ERA of 4.85.

Early struggles like these are common for freshman pitchers, though, most of whom are used to carving through lesser competition with minimal effort. Detmers quickly learned that falling behind college hitters will yield much less pleasant results, and went to pitch on the Cape the summer after his freshman year, where he did a better job of controlling the zone, cutting down the free passes, but still surrendered too many hits, pitching to an ERA of 4.55. He continued to show an ability to strike batters out, however, notching a little better than a strikeout per inning. During the time he wasn’t on the Cape, Detmers worked tirelessly on his mechanics to improve his control. He also re-dedicated himself to a fitness regimen to add strength and the ability to repeat those mechanics without tiring.

Detmers’ hard work over the summer paid off in his sophomore season, where he became the ace of Louisville’s staff, making 18 starts and winning 13 games. In 113 innings, he punched out 167 batters for a Gerrit Cole-like K% of 38%. His improved control showed itself in a much-lowered BB%, as well; in over twice as many innings pitched as his freshman year, Detmers walked one fewer batter. He led the Cardinals to the NCAA tournament and picked up a long list of accolades along the way, including being named a semifinalist for both the Golden Spikes and Dick Howser Awards, winning ACC Pitcher of the Year, and a host of other honors from various outlets. Detmers also spent this summer pitching for Team USA, which means there’s lots of helpful, recent footage of him:

Detmers’ fastball isn’t overwhelming, sitting 92-93, and with his maxed-out frame, that might be all there is, so his ability to command it is key. The pitch has a lot of arm-side run, so you can see why command might have been an early issue. Following his freshman year, Detmers started working a changeup and a cutter into his repertoire, but his real weapon is his nasty curve, which has good bite and depth:

That pitch is so nice, let’s see it twice:

There are very specific player archetypes many of us like (please direct all your undersized/pure hitter types to me, thank you), and I think “lefty with impeccable curveball” scratches a particular itch for many of you (our own Grant Bronsdon loves a humdinger curveball better than ice cream), so if that’s you, you will be very happy with a Detmers selection. If the Mariners do draft Detmers this spring, don’t get too attached to the idea of seeing him pitch in Everett right away, as Louisville looks poised to go on another World Series run after falling just short last year.