It may be time to recalibrate our opinion of Felix Doubront. For his first three-plus years, the tantalizing left-hander with the power arsenal frustrated more often than he wowed. The high pitch counts. The bullpen-taxing five-inning starts. The walks. The glacial pace. But something happened two months ago and Doubront has been a different pitcher since. On May 8, Doubront’s day to start, rookie Allen Webster got the call against the Twins. Doubront would be punted to the bullpen. Webster, as it turns out, had nothing, and Doubront entered with two outs in the second. The Sox trailed 8-5 and Doubront didn’t exactly stem the bleeding, allowing 11 hits and six runs in 51⁄3 innings of a 15-8 blowout loss. He finished the day with a 6.40 ERA and an uncertain future. He hasn’t been remotely the same pitcher since. Last night he kept the good times rolling in a 6-2 victory over the Angels. He went 62⁄3 innings, allowing five hits, striking out five, and flummoxing the hosts with a four-pitch mix that included a 94-mph fastball and one of his best changeups of the season. In the process, he lowered his ERA over his last 10 starts to 2.87. He has not allowed more than three earned runs in a single game during that time. His overall ERA, meanwhile, stands at 4.11, its lowest mark since the second inning of his season debut. “He has weapons. He has the assortment of pitches to keep guys off-balance,” Sox manager John Farrell said. “He’s kind of flown under the radar, given the years we’re getting out of some other guys, but he’s logging a lot of quality innings for us.” With Doubront pitching well, the Angels could not afford to make mistakes, but they gave the Red Sox two runs on defensive miscues, and then watched David Ortiz take a break from his night off to blast a game-breaking two-run homer in the eighth that still hasn’t come down.