The scouting report on Duffy, 27, has always centered on his electric stuff, but it also has had to mention his less-than-stellar command. That began to change this year as he ditched his windup to work permanently out of the stretch.
The theory behind the change was simple: Fewer moving parts, fewer things can go wrong.
"This year, the stretch has helped me immensely with my command," Duffy said. "I've watched a ton of guys that have exclusively pitched out of the stretch. [Indians right-hander Carlos] Carrasco is a guy who I've watched.
"There's no shame in that, and I don't know if I'll ever throw another pitch out of the windup, to be honest with you. It's very simplified, it's very nice. Clean, simple delivery."
Before Adam Eaton walked to start the game for the White Sox, Duffy had faced 88 straight hitters without a walk.
And as Duffy's numbers suggest -- his ERA dropped to 2.94 -- he isn't just serving pitches down the middle to avoid walks.
Duffy is commanding his fastball on both sides of the plate, and making hitters hit on his terms.
After tying a career-high with nine strikeouts in his last outing, he logged a new high with 10 strikeouts on Saturday.
The key, Duffy said, is knowing when not to throw a strike.
"I was telling [Kris Medlen], I texted him a minute ago, that I've never, in my whole career, tried to pitch around somebody," Duffy said. "I've always just gone right after people, and I just feel like my command is at the point where I can start to [pitch around hitters]. I can throw a pitch in a spot where it might not be a strike, but they might swing at it.
"Todd Frazier was an example today. He's a guy that can hurt you, you don't want to let their best guys beat you. But I pitched out of the zone a little to him. I've never really in my career tried to effectively pitch around somebody. It was cool. It was nice."
It was almost as nice as helping his team get a much-needed win.
"It's big, but it was a team effort," Duffy said. "Everybody contributed today."