clock menu more-arrow no yes

Filed under:

Here's how Danny Duffy can get better results in the rotation

New, comments

Duffy has started before and been both successful, though lucky in some ways, and below average. Something's gotta change.

Denny Medley-USA TODAY Sports

With Chris Young and Kris Medlen on the fritz in the rotation, there are some open spots. Now, both players had success for the Royals, but let's not sit here and pretend that there are not ways to improve. That's a harsh reality. Here's another harsh reality -- the Royals' options for improving here are limited.

What they have decided to do is put Dillon Gee and Danny Duffy in the rotation. Not having been stretched out, Duffy is on a pitch limit and will piggyback with another pitcher, likely Brian Flynn. Duffy has been a starter before; for his career, he has 80 starts and 426.2 innings for a paltry 5.1 innings per start.

With a K-BB% (a better measure than K/BB) in single digits, Duffy has relied on contact management for his primary method of getting outs. He has done reasonably well in this regard -- his career 3.90 ERA as a starter is a bit lower than his 4.32 FIP and 4.63 xFIP, peripherals suggesting he should be giving up more runs than he does.

Where Duffy excels in contact management is in generating popups. Duffy has a rising fastball, one of the more rising fastballs in the league. His 14.9 percent infield fly ball rate (Infield flies / fly balls) as a starter reflects that fastball. For context, the league average IFFB% for starters is 9.1 percent this year, and a 14.9 percent IFFB% would rank in the top 20 among qualified starters this year (out of 100).

Here's the thing, and I'll use two similar players to illustrate the thing. Consider Drew Pomeranz and Drew Smyly. You tell me if their story sounds familiar. The Drews are both ~27-year-old lefties with rising fastballs who in the past struggled to stay in the rotation. For Pomeranz, it's always been a control thing. For Smyly, it's always been a Tigers-bullpen-is-bad-let's-put-Smyly-there thing. Both players have been traded -- Smyly from the Tigers to the Rays in the David Price trade and Pomeranz from the Rockies to the Athletics to the Padres.

The point is that these guys have never staked their claim AND that they have similar traits to Duffman in terms of age and rising fastball. There's a huge difference right now, though. They're each striking out 30 percent of the batters they face.

Here is some additional reading on Pomeranz and Smyly that will help explain what they've been doing. Pomeranz 1Smyly 1Smyly 2Smyly 3. The gist of those articles is that those two guys are locating their fastballs higher, especially with two strikes, to take advantage of their rising fastballs. In case you don't want to click on those articles, here are some zone profiles. What they show is where the four-seam fastball (as classified by Brooks Baseball) is located with two strikes. Compare Smyly and Pomeranz to Duffy. These are from the catcher's point of view.

Drew Smyly since his trade to the Rays

drew smyly

Drew Pomeranz as a member of the Padres in 2016

drew pomeranz

Danny Duffy in 2014 and 2015

danny duffy

It is quite clear that Pomeranz and Smyly throw their rising fastballs high with two strikes. Duffy sometimes does it, sometimes does not. Mostly, Duffy locates his fastball on the outside corner against lefties and inside against righties.

The results bear out the approach. Smyly and Pomeranz have double-digit whiff rates on their four-seam fastballs, while Duffy's lags behind.

Duffy has an advantage over Smyly and Pomeranz, though. Velocity. The Drews are 91-92 with their four seamers; Duffy averaged 94.3 mph on his four seamer in 2014-2015. Duffy has the movement and velocity to strike hitters out; it's always felt like he should be striking out hitters left and right. He needs to adjust his approach; Duffy and the Royals should consider high fastballs to go along with his big, looping curveball to achieve a bigger difference in eye level and potentially more deception.

Aside from the fastball difference, there's a difference in the curveball as well. All three pitchers use it as a secondary pitch, Pomeranz especially. The Drews get almost double the whiffs on the pitch compared to Duffy. Now, the movement on the curveball for each pitcher is not quite the same, but the Drews clearly try to bury it in the lower left-hand corner of the zone profiles above. That's low and outside to lefties, back foot against righties. Here is Duffy's zone profile of the curveball from 2014 to 2015.

duffy curveball

So Duffy does that too, but not quite as well. Also, what the crap is that stuff in the top right corner? I don't know why Duffy tries to place a curveball up and away from righties; that's not a pitch likely to be called for a strike, and righties are definitely laying off the pitch. Duffy could tighten up this distribution; he's got a slider as well, and he's doing the same damn thing with it.

That covers the fastball and the secondary pitch. Smyly has a cutter as a third pitch, which gets a ton of whiffs but gets hit hard when hitters do make contact. Pomeranz has a changeup, but he uses it only against righties. For his third pitch, Duffy has two choices (if you lump his curveball and slider together as his secondary). He throws a sinker, which he should probably abandon as it gets neither whiffs nor grounders, and a changeup.

Historically, Duffy has used the changeup only against righties. That's pretty normal; he can get lefties out with his fastball and breaking ball. Unfortunately, the pitch just isn't all that good right now. In 2014 and 2015, hitters banged it up for a .289 / .519 BA / SLG. It gets a little over 10 percent whiffs, which is almost equal to his slider, but it does not do a good job of getting ground balls.

In terms of raw stuff, Duffy's changeup is not really bad. It gets a solid 10 mph in velocity separation from his fastball. The movement difference is there. Like with the fastball, it's another location thing. Consider the following two graphs, which show the location of Duffy's changeup and the location of swings against the changeup. As with everything else, 2014-2015 data.

duffy changeup location

He generally keeps it low or away, not much low and away. Remember that Duffy throws his changeup against lefties sparingly, so his primary usage of the changeup is low and inside to righties. That does not make much sense to me. There's no deception; there's no interplay with the fastball or the curveball. Hitters have taken notice.

duffy changeup swing location

Hitters are not swinging at the place where Duffy locates his changeup the most. Finally, here is where hitters whiff the most against the changeup.

duffy changeup whiff location

The changeup is quite clearly most effective low and away; Duffy is not throwing his changeup to the place where it is most effective.

Let's pull it all together. Duffy has great stuff - the velocity is there with his rising fastball, which generates popups. The changeup has the velocity differential and movement to be an average pitch (it seems to me). He's got breaking balls.

None of it is working together.

There is the concept in pitching of tunneling - you try to get your pitches to look the same up to a certain point, after which they diverge. The idea is that hitters have less time to decipher what is coming at them if everything is coming through a narrow tunnel. Based on where Duffy locates his pitches, I don't think there is any sort of tunneling going on. The fastball and changeup are not up and away. The breaking ball is not starting away and coming back in. It's starting over the middle and coming in further.

Simply put, Duffy is not locating his pitches where they will be most effective individually and as a repertoire. He's gotten by on pure stuff and velocity to keep the damage on contact limited, but hitters are just not fooled by what he is throwing.

The opportunity is there. Given his velocity, Duffy should be the best of the three.