Danny Duffy’s Greatest Game

Perhaps lost a bit in the trade-deadline shuffle, Kansas City left-hander Danny Duffy pitched one of the very best games of the year this past Monday. On the road against Tampa Bay, he had a no-hitter going until the eighth inning. By the time that inning had ended, Duffy had recorded 16 strikeouts against just one hit and one walk. After a fairly mediocre 2015 season spent mostly in the rotation, Duffy looked to be the next in line to become a very good reliever on a Royals team that has had its fair share. For the first month of the season Duffy pitched quite well out of the pen, but since the middle of May, he’s been a part of the rotation. Jeff Sullivan chronicled Duffy’s rise in the middle of June, noting in particular the lefty’s ability to throw for strikes, and hitters’ general inability to hit those strikes.

The numbers Sullivan cited in his post six weeks ago have remained good since then. Danny Duffy is generally a strike-thrower, keeping the ball in the zone 53% of the time this season, a figure which ranks sixth out of 95 qualified pitchers. Nor is he necessarily pitching to contact, however: his 78% Z-Contact rate is third in baseball behind only knuckleballer Steven Wright and Max Scherzer. Hitters haven’t fared too much better outside of the zone: his 56.6% O-Contact rate is 13th among qualifiers. His overall contact percentage (72%) and swinging-strike percentage (14.3%) sit behind only the figures produced by Jose Fernandez, Clayton Kershaw, Michael Pineda, Max Scherzer, and Noah Syndergaard. His 62% first-strike rate is good, but closer to the middle of the pack.

In Duffy’s brilliant game against he Rays, his first-strike percentage was actually a tad lower than normal at 53.9%, and his zone percentage was just a bit under 50%. Where Duffy excelled was getting the Rays to chase the ball outside the strike zone. Of the pitches outside of the strike zone, Rays batters swung at 44% of them and made contact on just 20% of swings.

Danny Duffy has four pitches, and three of the four are above average when it comes to whiff rate, with only the slider coming in a bit below. However, the slightly below-average whiff rate on the slider is mitigated by a high ground-ball rate. Duffy is a fly-ball pitcher — having recorded a 44.6% fly-ball rate that ranks ninth in baseball and a 35.2% ground ball that places seventh from the bottom — but the slider has induced ground balls on 52.6% of balls in play. The table below depicts league-average whiff rate for all pitchers, for left-handed pitchers, for Duffy in 2016, and for Duffy in his 16-K start against the Rays, per data from Baseball Savant and Brooks Baseball.

I have attempted to draw your attention to the ridiculous 53.8% whiff rate on the change. Duffy threw the pitch 26 times, hitters swung 19 times and they whiffed 14 times. That isn’t actually the high on the year for changeups; Jeremy Hellickson, David Price, and Matt Shoemaker have all recorded games with 16 whiffs on the change and Shoemaker has another three with 15 whiffs. Shoemaker actually has another two games with 14 and Kyle Hendricks has a game with 14, as well. (Brooks Baseball classifies Shoemaker’s pitch as a splitter.) The table below shows the pitchers with at least 14 whiffs on the change in a game, accompanied by the percentage of whiffs on the pitch.

Again, I would direct your attention to the highlighted portion, as Duffy’s percentage is the highest of the pitchers shown above. For some perspective on Duffy and the rest of the pitchers above, note that fewer than one in five starts in the majors this season has resulted in a pitcher recording at least 14 whiffs on all pitches. Duffy’s change has been good all year, but against the Rays, it was at its best. Duffy was getting more horizontal movement on the pitch, per this chart from Brooks Baseball.

On average, Duffy was getting close to two extra inches moving to his arm side on the change. Against left-handed batters, that meant that the pitch stayed outside, making it nearly impossible for the hitter to reach. Here it is against Nick Franklin getting nearly 13 inches of horizontal movement.

That pitch was darting down well out of the zone. Even when he left it up, though, it was difficult for Rays batters to find. Here it is against Tim Beckham in the eighth for what would be Duffy’s penultimate batter.

Of course, Duffy got whiffs on more pitches than just the change. He got 35 whiffs in all, which, as Daren Willman noted, is tied for most in the Statcast era. Taking that information, here is the highest percentage of whiffs for pitchers with at least 25 in one game (out of a total of 56 games).