A video session with pitching coach Dave Righetti showed Bumgarner that he had been reaching too far back in his delivery, which explained to him why he was feeling more fatigued than usual during his recent outings.
"I've always been a rotational guy, but Rags called me in and we looked at some video together," Bumgarner said. "I've been turning a little bit more than I used to. That causes a lot more stress on your body when you're trying to get back in the direction of home plate. We got that all worked out now, I think."
Bumgarner pitched himself out of the rotation in the National League Championship Series after the Cardinals tagged him for six runs in 3 2/3 innings in the series opener. The outing followed his Game 2 start in the NL Division Series when he allowed four runs in 4 1/3 innings against the Reds.
"I think throwing the way I was throwing was causing a lot more stress on my body, and that was causing me to tire out more quickly," Bumgarner said. "Whether you're tired or not, you have to go out and find a way to get the ball to go where you need it to go. I wasn't able to do that."
Bumgarner hasn't pitched in a game since Oct. 14, but he has worked on refining his delivery in several bullpen sessions, with the most recent one coming in the Giants' off-day workout Saturday.
"It feels a whole lot better now, but there's really no way to tell until you're out there in game speed," Bumgarner said. "I think we're good and ready to go."
A regular season that brought him a career-best 16 wins also had him fighting his mechanics toward the end of the season, particularly a four-start stretch at the end of August and early September. He posted a 7.28 ERA in those four outings, but rebounded with two strong starts in which he allowed three runs in 11 2/3 combined innings after tweaking his delivery and mechanics during bullpen sessions.
"I wish your body could just lock in and do the same thing every time out, but there's always little stuff that goes on," Bumgarner said. "A lot of times people will catch it and fix it a lot sooner before you realize what you're doing."