When the Detroit Tigers took Daniel Stumpf in the 2017 Rule 5 draft, educated fans had two main reactions. Dismay was first and foremost — many wanted some catcher whose name I can never seem to remember. Second was a curiosity as to who the heck the guy was. The numbers told of a mediocre left-handed pitcher who couldn’t make it the season before and probably wouldn’t make it on his second time around either.
From that perspective, Stumpf has been a raging success. He took a nonlinear route to his role on the team — one that included being offered back to the Kansas City Royals and a minor league deal that saw him pitch 24 games with the Mud Hens. The majority of his season, though, was spent in a major league uniform and he proved effective enough against MLB hitters.
That said, his numbers have been closer to those of useful bullpen depth than a remarkable reliever.
Daniel Stumpf Statistics, 2017-2018
Under the Brad Ausmus regime, Stumpf made appearances during the the eighth or ninth inning 45.1 percent of the time. Since Ron Gardenhire has taken the wheel, that rate has jumped to 52.6 percent of the time. For managers with an old-school mentality like these two, the later innings represent high-leverage situations. Only the best in a traditional manager’s bullpen get to pitch late in games. To see Stumpf get that many of his innings in such a role is a bit surprising.
It’s hard to visualize a late-game pitcher emerging from those stats. He doesn’t whiff too many batters. His strikeout rate has fallen to a mere 17.9 percent on the season despite inducing swings on pitches outside the zone at an above-average rate. That can be explained by an above-average rate of contact on his pitches out of the strike zone.
That out-of-zone contact rate becomes an issue for a pitcher like Stumpf. While he is really only useful when he gets the batter to whiff, he’s sporting a swinging strike rate that is sitting just one percent above average. One of the few factors in his favor is his low average exit velocity — Stumpf ranks 23rd among pitchers with at least 25 batted balls with an 84.5 mile per hour exit velocity. Aside from that tidbit, though, the results aren’t what you’d hope.
Stumpf rarely induces weak contact, with a 9.8 percent rate that ranks among the worst in league. His line drive rate doesn’t compare quite so unfavorably to his peers, but is still well higher than it should be. Add in a ground ball rate that falls below league average, and the deal is sealed.
Stumpf also isn’t really all that great against lefties. He has certainly pitched better against left-handed hitters than those who take their cuts from the right side, but nothing he does inspires much confidence. A quick glance at the stats uncovers a pitcher who strikes out lefties at a rate that exceeds MLB average and walks them at a lower clip. Don’t get your hopes up, though. He betters the league by a mere one percent in punchouts and falls just under three percent fewer walks.
Long story short, better than league average doesn’t exactly make me feel warm fuzzies, especially since “league average” includes all the righties that are awful against lefties.
None of this is to meant to prove that Stumpf has no place on the team. Detroit’s bullpen is weak enough before injuries take their toll. But he should not be used as the team’s primary left-handed option out of the bullpen, where Detroit’s managers seem to have placed him.