Jon Lester threw a no-hitter in his first career complete game yesterday, though his peripherals don’t look as good as the result.

Lester struck out nine and only issued two walks in the game, and improved to 3-2 with a 3.41 ERA and 1.30 WHIP. He’s striking out batters at a 5.73/9 rate, and his BB/9 thus far is 4.23. The Hardball Times puts his xFIP at 4.36, about one full point above his current ERA, and he’s cruising along this year with a .254 BABIP. Though Lester hasn’t yet pitched a full season in the majors, he appeared in fifteen games in 2006, when he posted a 6.64 K/9 and 4.76 BB/9, and twelve last year, when he had a 7.14 K/9 and 4.43 BB/9.

Taking all this into consideration, his strikeout rate seems somewhat off from his career numbers, while his walk rate fits right in line with what he’s done before. If he can’t raise his K rate this year, his luck metrics might put him in some high-ERA danger down the road. What’s more, he’s getting a 50.8% groundball rate, which is great, but far from his previous 40.6% (2006) and 34.4% (2007), meaning it may be due to regress as well as the season goes on.