Danny Duffy PITCHf/x

Here’s something new. Jeffrey Gross from THT Fantasy and I are exchanging “watch this guy” ideas—fantasy picks from one side and PITCHf/x based picks on the other. First up is Jeff’s first breakout candidate for a cheap but valuable pitcher—Kansas City’s Danny Duffy.

The PITCHf/x data we’re discussing can be seen on Duffy’s player card at Brooks Baseball. The data is from MLB Advanced Media (‘BAM) but the pitch classifications are our own. Duffy pitched in the majors from May to September in 2011, ending his season after one start in that final month. It was his first year in the show, although there are some PITCHf/x data points from the 2009 Futures Games, the Arizona Fall League in 2010 and some Cactus League action from 2011.

Duffy’s primary pitch is his four-seam fastball, followed by a curveball, change-up and the occasional two-seam fastball and slider.

Horizontal spin movement and vertical spin movement+gravity

vs LHH
vs RHH

shown from catcher’s perspective

The black blobs at the top are four-seam fastballs, straightest flight and the backspin keeps gravity at bay fairly well. He’s got a good hopping fastball, generates pop-ups and fly balls. To the right of the fastballs, running down and away from right-handed batters and rarely thrown to left-handed batters, are his two-seam fastballs or sinkers if you prefer. The blue dot change-ups have a similar tail to the sinkers but their reduced speed gives them separation vertically. The yellow curveballs are a group of over-the-toppers with a red cherry of the occasional slider on top.

Fastball (FA) 94 mph, 62% usage
Curveball (CU) 76, 19%
Change-up (CH) 84, 14%
Sinker (SI) 93, 3%
Slider (SL) 81, 2%

Duffy’s fastball is above average in whiff rate, pop-up rate and flyball rate compared to other fastballs. His change-up is mostly average but his curveball doesn’t miss too many bats but yields plenty of ground balls. At least in 2011, that is. He’s yet to develop a swing-and-miss secondary pitch, and that’s going to hold him back. You can’t pitch on fastballs alone in a big league rotation. Or not for long.

If he’s going to rely on his impressive power, he would benefit in the long run by further develop his two-seamer, which was ineffective in yielding worm killers in its limited use. With his high arm slot, a true sinker isn’t likely to emerge. He may get more ground balls out of a cut fastball if he were to develop one.

Some trends to note before we hand the baton to Jeff for his Fantasy perspectives … caveats are the small sample size and the PITCHf/x data from Kansas City tending to yield higher pitch speeds than most other parks.

  1. Duffy’s whiff rate trended downward as the season progressed (May: .25, June & July: .22, August: .15, September: .17)
  2. Duffy’s fastball speed declined in late July, recovering briefly before declining steadily through his last start. His final five starts: 94.4 mph, 94.1, 93.7, 93.4 and 92.7
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  4. Despite showing some signs of fatigue (speed and whiffs dropping), Duffy’s highest pitch count came in that final start on Sept. 6, throwing 119 after not crossing 105 in his other starts

Jeff’s thought was 2012 could be a breakout year for Duffy. I’d watch him with an eye on 2013.

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Mark Himmelstein
Mark Himmelstein

I’m not a Pitch F/X whiz, but I agree with Jeff that Duffy’s someone I’m very interested to watch. I remember reading another Pitch F/X analysis that he perhaps left too many curveballs in the middle to upper portion of the strike zone, which helps explain the lack of whiffs and high contact rate on the pitch. Just statistically/narratively, the guy I keep coming back to with Duffy is Jon Lester. They’re both big lefties who throw hard and rely primarily on the four seam/curveball combo. They were both well regarded high school arms who were drafted early but outside… Read more »

Lucas Apostoleris
Lucas Apostoleris

Duffy’s apparently been mixing in a cutter this spring, so we’ll have to keep an eye out for that as well.

Harry Pavlidis
Harry Pavlidis

Hmm, so Duffy is working in the cutter … maybe Jeff is right about 2012 being the breakout.

Mark – thanks for the comment, that’s a fascinating comparison.