PITTSBURGH -- Roansy Contreras has more trust in his slider this year compared to last year, and on nights like Thursday, that trust was rewarded.

Contreras not only allowed one lone run across 6 2/3 innings with eight strikeouts in the Pirates’ 4-3 win over the Reds at PNC Park, the 10th consecutive quality start by Pittsburgh’s rotation, but he also generated a career-high 14 whiffs with his slider, the latest demonstration of the 23-year-old’s evolution.

“I feel pretty comfortable with the slider right now as my second pitch,” Contreras said through team interpreter Stephen Morales. “That’s given me the confidence to throw it any time in any count."

Along with generating so many swings and misses, Contreras filled up the zone with his slider, totaling a career-high nine called strikes. It shouldn’t come as a surprise, then, that all eight of Contreras’s strikeouts came via the slider -- seven swinging, one looking. Contreras wasn’t afraid to spam sliders either; against the Reds, there were four instances in which Contreras threw at least five consecutive sliders.

“In my opinion, I feel like he didn’t have his best stuff tonight. It still looked the way it did,” said third baseman Ke’Bryan Hayes. “Whenever he got behind, he was able to get that ground ball and ultimately came up with some big strikeouts. It’s just fun to see him throw each time he’s out there. I feel like we grow each and every time he takes the mound."

Added Reds manager David Bell: "He has a good fastball, but his slider was excellent. It was tough hitting. You do have to give them credit.”

After throwing 50 sliders in the series opener, the pitch now accounts for 45.7 percent of those Contreras has thrown this season. In 2022, by comparison, Contreras threw his slider 34.2 percent of the time. While the jump from ‘22 to ‘23 is stark, this trend of increased slider usage dates back to last summer.

In June 2022, his first full month at the Major League level, Contreras threw his four-seamer 50.9 percent of the time and his slider 29.3 percent of the time. In September 2022, by contrast, Contreras threw his four-seam fastball 42.4 percent of the time and his slider 43.3 percent of the time. That was the the first month in which he threw more sliders than fastballs. In his first four starts this season, Contreras is continuing to build on that formula.

"Trust is the key word there; trust the ability to execute pitches at any time,” said manager Derek Shelton. “I think he has that trust in the slider now, that he can go to it as a strike pitch and it's not just a chase pitch."

“That’s probably the evolution of baseball right now,” said catcher Austin Hedges. “You’ve got to be able to spin the ball whenever you can. Guys in this league hit fastballs. If you can’t hit a fastball in this league, it’s tough to play in the big leagues. When you’re behind in the count and fastball counts, if you can be able to rip a slider, that’s how you last in this league. He showed today that he’s got the ability to do that.” 

The only bit of trouble Contreras found himself in on Thursday came in the seventh inning, where he received a boost from his defense and his bullpen.

After allowing a single to Jake Fraley and walking Tyler Stephenson to begin the inning, Contreras induced a 5-4-3 double play, with third baseman Hayes making a Gold Glove-caliber slick stop on one end and first baseman Carlos Santana making a textbook pick on the other end. Jason Vosler ended Contreras’ night with an RBI single, the only blemish on his line, but Robert Stephenson came on in relief and struck out Nick Senzel to end the inning. 

“I kind of just blacked out,” Hayes said of the double play. “Athleticism kind of took over. I actually watched it back. I didn’t really realize what I did.”

“That's why he's one of the best defenders on the planet,” Shelton said. “There's probably two guys in baseball that make that play.”

With Thursday's outing, Contreras has thrown back-to-back quality starts for the first time in his Major League career, after having just three last season. He continues to grow with his slider in tow, and with a full season’s workload ahead of him, it will be worth watching how many strides he makes.