Ken Giles can still recall the first time he threw a 100-mph pitch.

Giles was a sophomore at Yavapai College in Prescott, Arizona when he clocked a triple-digit heater, which had been a long-time goal of his.

The 23-year-old rookie's emergence this season has added a power arm to what has become a solid and effective bullpen for the Philadelphia Phillies.

"I will always remember that day," Giles said. "It's one of those things I can say is a great accomplishment. Everybody knew I had that great fastball. But showing people I can also command around the zone and have that secondary pitch, I'm being known as a pitcher and not just a thrower."

Giles' slider has been a key in his dominance at the big league level. Although he didn't have great command of it before getting called up on June 7, he stopped thinking about his slider and instead focused on just throwing the ball.

The results have been impressive. Giles owns a 1.50 ERA with 36 strikeouts in 24 innings.

"I've always known I could do it," Giles said of pitching in the majors. "I guess it's one of those things – I went out there and did it. I just go out there and do the best I can do."

Giles isn't the only reason the Phillies' bullpen has been on a roll. Collectively, the bullpen has posted a 0.99 ERA over its last 27 2/3 innings, allowing only three earned runs. And since Aug. 5, their 0.36 ERA ranks second among all bullpens. During that stretch, they have struck out 30 batters while giving up only 13 hits and limiting opponents to a .140 average.