Danny Duffy: second-half breakout candidate

All stats current through July 21.

Danny Duffy | Royals | SP | 1 percent Yahoo ownership
YTD: 4.58 ERA, 1.58 WHIP, 7.5 K/9, 4.1 BB/9, 1.8 K/BB, 41.1% GB%
Oliver ROS: 4.89 ERA, 1.41 WHIP, 6.9 K/9, 3.3 BB/9, 2.1 K/BB

Entering the season, the Royals’ farm system was touted by many as potentially the best of the decade. Mike Moustakas and Eric Hosmer were knocking on the big-league door. There were the warm bodies of Wilson Betemit, Mike Aviles (who I still believe he can be a useful fantasy player, though his real life value is pretty nil) and last-chance Kila Ka’aihue.

With Zack Greinke shipped off for what some called a king’s ransom (though what the Royals got for him was arguably paltry in comparison to the Matt Garza haul), and with a slew of close-to-ready impact arms (Mike Montgomery, John Lamb, Jake Odorizzi, Danny Duffy) to anchor a cheap, effective long-term staff, many baseball analysts wondered whether they should in fact “Trust The Process” that Dayton Moore had been patiently preaching since taking over as the team’s general manager.

But minor league talent is fickle, and what looked great in the preseason has not exactly materialized into much excitement halfway through 2011. Wil Myers, like the Yankees’ Jesus Montero, is young for his level but has taken a few steps in the wrong direction this year in his transition from catcher to outfielder. Montgomery’s control continues to elude him in the upper minors this year. Lefty “ace” prospect Lamb has seen his strikeout rate tumble, and his walk rate rise, as he has moved through the Royals’ system. At 21 years old, there is plenty of room for him to grow, but Tommy John surgery will sideline him for the next 12 to 18 months.

Elsewhere, Kila continues to establish himself as a Quad-A player with power potential that seems to alternate by year. In the majors Billy Butler, king of the GiDP, seems increasingly less likely to see those doubles turn into homers given his near-50 percent groundball rate and home park.

Neither Moustakas nor Hosmer has been anything special yet. The hype on these two clearly set the bar too high too soon, something I cautioned about in the preseason. Both are plenty young with too little time in the majors to draw any substantial conclusions, but who would have thought that Moustakas, mired in a 2-for-47 slump, would be batting a paltry .190/.252/.241 with a .052 ISO that is dead on par with Juan Pierre? Hosmer (269/.323/.432 line and .327 wOBA, which is four percent better than the average player when park is considered) has fared much better, but he has been chopping balls into the ground a la Butler.

And that Danny Duffy guy? While a 4.58 ERA and 4.08 xFIP might have been average/slightly above average a few years ago, in the second “year of the pitcher,” those figures are 16 and four percent worse than the major league average, respectively.

All in all, the Royals have barely managed to win 40 games thus far this year, and their 58 losses are the most in the AL. They’ve been just as bad as the Cubs, despite being in a weaker division. While no one really expected the Royals to compete this year (no matter what they did through most of April), this cannot exactly be the state of the team fans expected headed into the season, right? I would show a little pity for a team that has not been to the playoffs since they won the World Series in the ’80s, before I was born, but the Cubs have not been to a World Series even in my father’s lifetime (he’s a Cardinals fan, so he’s not complaining), and thus my empathy here can only go so far.

But Royals fans, for all the misery of 2011, there a bright spot has emerged: Danny Duffy. Yes, that same Danny Duffy with an ERA, FIP, xFIP, SIERRA, and ERA that are all worse than the major league average.

Lost in Duffy’s 11 starts and 59 major league innings this year is how drastically different a pitcher he has been over his past five games compared to his first six. Take a gander:

Grouping IP Pitches/IP ERA WHIP K% BB% xFIP FB Velo SwStr% GB%
First Six 30.1 19.2 5.04 1.78 14.5% 15.2% 5.35 93.3 MPH 8.1% 41.1%
Past Five 28.2 16.4 4.08 1.36 23.6% 4.9% 2.93 93.9 MPH 9.6% 41.2%
MLB AVG N/A 16.1 3.80 1.30 18.4% 8.1% 3.83 91.7 MPH 8.5% 42.2%

What you might notice from this table is that although the results (ERA, WHIP) have not been pretty, Duffy’s efficiency and peripherals have substantially improved. While Duffy was having issues getting batters to swing (and miss) early in the season, he’s been throwing more strikes (59.8 percent in first six, 64.4 percent over past five), which has helped him not only cut his walk rate, but also convince batters that they need to swing at his offerings to get on base, leading to more strikeouts. Best of all, Duffy has been able to do this without sacrificing ground balls. Check out the difference in the location of his pitches between his first six and past five starts, courtesy of Texas Leaguer’s amazing PITCHf/x tool:

First six:

Past five:

What the image above shows is that not only has Duffy of late has been throwing more pitches in the zone, but those pitches outside the zone have generally been less spread out, less clearly non-strikes. The result has been that Duffy has pitched in form, though not in result, like the top talent he was in the minor leagues, where he owned a 2.65 ERA, a 1.11 WHIP, a 10.5 K/9, a 2.8 BB/9, and a 3.70 K/BB ratio. And those numbers are not the pure byproduct of early, lower minor dominance. At Triple-A this year, Duffy pitched 42.0 innings of 3.43 ERA, 1.12 WHIP baseball with 48 punch-outs to only 10 walks.

Plugging Duffy’s past five major league outings into the latest version of the xWHIP Calculator, we get a further sense of just how well Duffy has been pitching, even if his ERA and WHIP claim otherwise:


A 3.30 eFIP and 1.13 xWHIP performance would put Duffy in class with such starting pitchers as Tim Lincecum and Anibal Sanchez. Those strong numbers look even better in light of a league mean eFIP and xWHIP of 4.00 and 1.33.

If we adjust Duffy’s eFIP to reflect the current state of pitching, then it would be somewhere between 3.15 and 3.20. Duffy has exhibited pretty good control in the minors, and walk rates tend to translate into the major leagues, especially when the relevant numbers come from the upper minors. Hence it is possible, even though walk rates take substantially longer than 35 innings to “stabilize” and become statistically significant, that Duffy could end up with a strikeout-per-nine rate above eight, a walk rate below three, and a slightly above-average groundball rate. Particularly as a hard-throwing (93.6 mph fastball) southpaw in one of baseball’s weakest divisions and at one of baseball’s most pitcher-friendly parks, Duffy’s second half has the potential to be dominant if he continues to pitch as he has of late.

In my humble opinion, it’s time to visit Duff Gardens. While I wouldn’t drink the water from the river, I’ll certainly drink the Kool-Aid.

Recommendation: Danny Duffy is a must-own AL-only commodity and should be owned in deeper mixed leagues (those with 12 or more teams and innings caps of or above 1,300). Duffy should rank as a top 50, potentially top 35-40, starting pitcher in mixed leagues for the rest of the season.

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  1. Brandon said...

    Good work! This blows ESPN’s $portsbizcorp insider garbage out of the water. Keep it up. +1 reader.

  2. Brian said...

    awesome, Jeff.  Could actually be kinda neat to do something similar with Ubaldo with his first 9 starts vs his most recent 10 starts (no more than 3 ER). xFIP by month: 4.47, 4.33, 3.20, 2.25.  I have an obsession with Ubaldo, and it may or may not have to do with this:  http://www.sbnation.com/2010/6/3/1499549/ubaldo-jimenez-throw-best-pitch-ever

    I might take this on and analyze Ubaldo the way you did Duffy.  Especially with his GB% going (by month) 40%, 46%, 48%, 51%.  Fun exercise, anyway.

  3. Jeffrey Gross said...


    Cool. He’s actually on my list of guys for my next WW article. I have 3 NL, 3 AL breakout guys for the second half:

    Javier Vazquez (article came out last week)
    Ubaldo Jimenez (post-hype)
    Chris Capuano

    Danny Duffy
    Felipe Paulino
    Brandon Morrow (post-hype)

  4. Dan said...

    First of all, love the analysis AND the Simpsons reference—you’ve got a new reader.

    Buuuut, as an obsessive Royals fan, I need to clear one thing up: “While no one really expected the Royals to compete this year (no matter what they did through most of April), this cannot exactly be the state of the team fans expected headed into the season, right?”

    I promise you, that is pretty much exactly what we thought was coming.

    http://www.royalsauthority.com/?p=3836 (about minute 37)

    These are the most optimistic and prominent Royals blogs…and they are mostly trying to convince the reader that 100 losses is not a sure thing.  Royals fans are beaten down, depressed, and we hate the world.  Also, I think most of us are fine with 2013 being the jumping off point for trying.  If Duffy and Paulino do step up, the Royals will only need 3 more starters by 2013.  C’mon, Montgomery’s control and Odorizzi generally!

  5. Jeffrey Gross said...


    Glad you enjoyed the article. Maybe I just selectively read Rany’s tweets. I got some sense Royals fans thought they could win 80 this year, which I thought was a pipedream. I’m not nearly as enamored with the farm system as most.

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