As a junior at Wake Forest, he tossed a nine-inning no-hitter against Marshall on March 3. In that game, he hit three batters, walked another and even allowed a run in a 5-1 win.
On Friday, he was perfect through six innings in the second game of a doubleheader for short-season Tri-City. That meant the 21-year-old left-hander was three outs away from his first perfect game at any level.
His previous experience shouldn't suggest that Holmes, the Astros' 13th-round pick in last month's Draft, drew any particular insight with a chance to make New York-Penn League history.
"I feel like you have to go out there and approach everything the same," Holmes said. "You can't change much. You just need to focus on getting one out after another, and that's how you get a good outing."
Unfortunately for Holmes, the next out did not come.
The southpaw allowed a single to Joey Rickard on the first pitch of the seventh. He retired the next three Renegades to wrap up a one-hitter as the ValleyCats blanked Hudson Valley, 7-0.
Like any flirtation with a gem, Holmes had one regret.
"Honestly, I threw a fastball in when I shouldn't have," said the Georgia native, who also possesses a changeup, curveball and slider. "In that game situation, where it's the first batter of an inning and he's seen me a few times, I should have thrown a breaking ball."
A four-run seventh by the ValleyCats didn't help, either. While his teammates were filling up the box score, Holmes didn't have much to do but think about the feat at hand.
"I never hope anything but the best for my teammates, so it's not like I was mad they were scoring runs," he said. "But it was a long inning and I didn't have much else to do but think about the perfect game. It probably added to the nerves a little."
The former Demon Deacon improved to 4-1 with a 2.55 ERA and 33 strikeouts over 35 1/3 innings in seven pro starts. He has allowed only one run on six hits in his last three starts after surrendering seven earned runs on six hits and four walks in a 3 1/3-inning stint on July 8.
The big difference has been his use of the fastball, the pitch that was behind much of his success Friday -- but also his one mistake.
"My command has been a lot better," said Holmes, who has not walked a batter in his last two starts. "In that one start, I struggled. I was leaving the fastball over the plate way too much or I was getting behind guys. Lately, I've been focusing more on getting that first-pitch strike, and the results have been there."
As he continues his rookie season, it seems the more quality outings Holmes logs, the better he feels about his decision to leave Wake Forest with one year of eligibility remaining.
"It's been really fun so far," he said. "It's been different playing every day, but that's part of the reason I came out of school. I wanted to play the game I loved for a living."