Sims, the Braves' No. 19 prospect according to MLBPipeline.com, allowed four earned runs but struck out a career-high seven over 6 1/3 innings, the longest performance of his brief career. Allowing just one run through his first five frames, he gave up back-to-back doubles in the sixth and a solo homer in the seventh to push the Phillies' lead out of Atlanta's reach.
"He was in a position where he wasn't afforded the luxury of giving up anything in the game tonight," Braves manager Brian Snitker said. "But the kid never quits and he keeps pitching, and I'm sure he'd like to have a better outcome, but overall, it's one of those games where one run is almost too much."
"Best my stuff has felt since I've been up here, and to go out there and not execute when I needed to [is unfortunate], but it's a learning experience," Sims said.
Sims has increasingly relied more and more on his slider, throwing it 30 percent of the time over his last two outings. On Monday, he threw a career-high 38 sliders of his 99 pitches. But it wasn't just the slider. Sims also threw 18 curveballs, his most in a game. The offspeed pitches kept Philadelphia off balance. The Phillies' eight hits off Sims came off a fastball or changeup, and they went 0-for-9 against his slider and curveball.
His curveball played as an out pitch, accounting for five of his seven strikeouts. His previous high strikeout total in a start was four, a number he eclipsed Monday with just his curveball.
Philadelphia's first run came on a 2-2 fastball that caught too much of the plate for Phillies starter Aaron Nola in the third inning.
"I wish he had thrown [a breaking ball] to the pitcher," Snitker said.
Even if Sims expected it of himself, pitching into the seventh inning for the first time in the Majors was a small victory. And he was only able to get there because his two breaking balls were on point.
"It's my job. That's what I expect out of myself, to go out there and go deep, get as many outs and zeros as I can," Sims said. "Today I didn't do my job as well as I should have."
While not earth-shattering, the start is a good one to keep in his back pocket. The outing featured flashes of potential from the Braves' 2012 first-round Draft pick. Six starts into his big league career, that's a victory, despite what the scorebook may read.
Ben Harris is a reporter for MLB.com based in Philadelphia who covered the Braves on Monday.