Kansas City Royals Danny Duffy and the Case of the Ineffective Fastball


It’s bad when a guy makes it through five innings on 100+ pitches and everyone acknowledges it as a step in the right direction, but that’s exactly what happened last weekend with the Kansas City Royals Danny Duffy versus the New York Yankees.

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This comes after a couple of even more horrible starts, of course, that saw Duffy throw a total of 142 pitches in 4.2 innings. So yes…the 113 pitches in 5 innings was definitely better, but still not where he needs to be (obviously).

So what’s going on?

Looking back at 2014, Duffy had a 2.53 ERA in 149.1 innings (with a 3.83 FIP). During that time, according to Brooks Baseball, Duffy threw his four seam fastball 58.23 percent of the time, with the curve being his second most thrown pitch at 13.74 percent.

2015 has been a different story, though. The fastball usage is down to 45.53 percent with the curve in very diminished usage at 2.09 percent. That’s the least he’s thrown the curve since, well, ever. He’s throwing his slider at 24.16 percent this year after only using it 8 percent of the time in 2014 (and prior to that, never having used it more than 2.78 percent of the time).

Another difference this year – he’s throwing harder. His four seamer is up almost one mile per hour over 2014 and the sinker/two seamer is up in velocity as well. His change is up more than two MPH as is the slider. The last time Duffy threw his four seam fastball at an average of more than 95 MPH (for an entire season) was in 2012, when he made just 6 starts and threw 27.2 innings in the big leagues. During that small sample size, he also had 5.9 BB/9 (the highest rate in his career).

That being said, pinpoint control has never really been Duffy’s strength. For his career (now spanning 345 innings pitched), Duffy has a 4.0 BB/9. However, when Duffy eased off on velocity in 2014, dropping his average four seam fastball to 94.21 MPH, he had his best results with just 3.2 BB/9. That number was 1.2 BB/9 less than his previous best of 4.4 BB/9 over 105 innings in 2011. How much harder is he throwing this year? Well, in 2014, he threw every pitch in his repertoire, with the exception of his curve, at a lower velocity than what he’s thrown this year.

So what can we take away from all of this information? Most obviously, for whatever reason, he’s not comfortable relying on the curve this year. That reason seems to be his control…or lack of in this case. Duffy threw the curve in the strike zone 33.95 percent of the time last year. This year, that number is all the way down to 13.33 percent.

Now, the curve being in the zone doesn’t necessarily matter…the movement is generally going to place the pitch outside the zone anyway. What matters is getting batters to swing  at the pitch and miss – or at least make poor contact. But 13 percent is pretty low. You can see the zones below in relation to his curveball placement…he didn’t leave many of them up high in 2014. This year, they’ve almost all been high.

Let’s take a look at the placement of his curve (first in 2014, followed by 2015).

2014 Zone Profile – Curveballs

2015 Zone Profile – Curveballs

So maybe Duffy doesn’t have the feel for the curve that he’d like to have, but opponents still aren’t hitting it with any success…the batting average of opponents versus the curve in 2015 is zero. So maybe the curve isn’t the problem. Maybe the increased slider use (with a .163 BAA) isn’t the problem either. Maybe it’s the four seam and the sinker.

2015 Pitch Outcomes

2015 Results and Averages

For the 2015 season, opponents are crushing both fastballs – especially the sinker – but are having very little success against his off speed pitches. Now, compare the above chart to his 2014 results:

2014 Pitch Outcomes

2014 Results and Averages

The fastballs were both much more effective last year. Opponents had lower BAA versus those two pitches and there was a higher whiff rate. Somewhere along the way, Duffy has completely lost something on these pitches (not velocity) or the league has adjusted, meaning Duffy needs to make an adjustment of his own. If he can’t establish that four seamer…his other pitches aren’t going to work, either. You can see in the above charts that batters aren’t swinging at the off speed stuff as much in 2015. And they won’t when they can hit the four seamer and the sinker at higher line drive rates for BAA of .382 and .400, respectively.

Seems to me – the armchair pitching coach – the simple answer is to take a little something off the fastball.  After ramping up the speed in his two worst starts, Duffy backed off against the Yankees and had a somewhat better outing. So far, he hasn’t had a game this year, though, with an average four seam fastball below 94 MPH. In 2014, after six relief appearances, Duffy made his first start. His average fastball speed that game was 96.01, but after that? He took a little something off, maybe giving him better command. His average in May 2014 was 94.39, in June it was 94.30, July was 93.90, August was 93.93, and September saw him all the way down to 92.41 – but we’ll throw that out (he threw 8 innings and was battling an injury at that point). Still though…you get the point.

Unfortunately, until Duffy figures it out, I’d expect a lot more of the same. We could be breaking down Joe Blanton’s first start as a member of the Kansas City Royals if Duffy doesn’t straighten things out against the Cardinals this weekend. He may have a longer leash than some guys…but something’s got to give.

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