On Tuesday, Dave Duncan appeared on Bernie Miklasz’s radio show and talked about Mitchell Boggs’ surprising demotion to Memphis. Bernie summarized the conversation in his Bytes section at STL-Today:
Cardinals pitching coach Dave Duncan was a guest on my radio show Tuesday and made a lot of sense when he discussed the demotion of Mitchell Boggs. Duncan said Boggs had lost confidence in his slider, had abandoned throwing the changeup, and was overly reliant on his fastball. Duncan believes Boggs needs plenty of work to re-establish the slider and the changeup and so a tune-up visit to Memphis was the best way to go, simply because Boggs had in effect fallen behind Fernando Salas, Eduardo Sanchez and Jason Motte in the RH reliever cast.
I thought this angle on the demotion would be easy enough to investigate with pitch f/x data available at Texas Leaguers. So… has Mitchell Boggs really been throwing more fastballs?
If Boggs abandoned his changeup, it must’ve happened in college or the minors because he’s never thrown it much in the big leagues. While he toyed around with a curveball and changeup early on in his career as a starting pitcher, he pretty much gave up on them as soon as he became a member of the bullpen. Though Boggs slightly changed his fastball/slider usage after blowing the save in Houston on April 27, it wasn’t exactly a drastic shift. It’s a curious assertion that he had lost confidence in the pitch considering that it had been his most valuable weapon this season, and even more effective than it had been last year (at least according to Fangraphs’ pitch type linear weights).
I don’t mean to question Duncan’s integrity. It’s quite possible that Boggs admitted to diminished confidence in a private conversation, but that’s a peculiar scenario given that he still threw off-speed pitches about twenty percent of the time and had been getting better results than ever before.
I’d be surprised if Boggs spent a significant amount of time in Memphis, so I won’t overreact to the move. It should be noted, however, that he leads the Cardinals’ bullpen in xFIP (2.85) and K/BB (4.75). At VEB the other day, Tom S. pointed his finger at those relievers who should’ve been on the chopping block first. It seems pretty clear that this move was made to buy time for the careers of Franklin and Batista. But if the path of least resistance is what the club desired most, why not just send Pete Kozma back to triple-A?