Ken Giles threw 18 seventh-inning pitches to retire the top of the Marlins lineup Tuesday night. Fifteen were strikes. Jake Marisnick rolled a 97-m.p.h. fastball to third. Derek Dietrich whiffed at a 97-m.p.h. fastball. Giancarlo Stanton struck out for the second time in as many nights against Giles.

The 23-year-old reliever with his hat brim pulled down did not pump his fist or yell. The Phillies led 7-2 in a game they would win 7-4, and these were just three more outs for a young pitcher who looks like he belongs.

It is difficult to find fault in Giles' first six major-league appearances. He arrived amid hype for his 100-m.p.h. fastball. When he pitches, fans fix their attention to the radar-gun readings in right field. But it is his slider that is the most impressive pitch.

Giles has struck out 12 of 21 batters faced. Those hitters have swung and missed at 24 percent of Giles' pitches; the league average is 16 percent. He was known in the minors for his fastball, but the slider has fooled hitters the most. That qualifies as the most encouraging development.

Batters are 0 for 10 against Giles' sider with eight strikeouts. He has thrown the pitch 42 times. It has been put in play just twice — once for a groundout and another for an infield pop out. A hitter has swung and missed at Giles' slider 15 times.

Giles permitted a home run to the first batter he faced, and just one hit with two walks since. There will be some adversity to overcome — hitters will make adjustments and Giles will have to counter — but he appears equipped to succeed at this level.

No Phillies reliever has ever struck out 12 batters over his first six major-league appearances, according to a search. Wayne Twitchell (1971), Warren Brusstar (1977) and Ryan Madson (2004) fanned 11, all in more innings than Giles.

It is a fine start.

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