Clay Buchholz’ first playoff start ended with a punch to the gut. Surely, you remember it. Pitching in do-or-die Game 3 of the 2009 AL Division Series, Buchholz yielded two runs to the Los Angeles Angels and left with the Red Sox leading, 5-2, in the sixth inning. But Billy Wagner gave up two runs in the eighth, closer Jonathan Papelbon allowed three in the ninth, and the Sox were swept away in a 7-6 crusher. Still, as Buchholz trudged out of Fenway Park and into the offseason, he was buoyed by one thought. “Getting that first taste of being able to pitch in the postseason,” Buchholz recalled last week, “I thought, yeah, we can make this an every-year occasion. You kind of get a little spoiled.”