Droll and clearly disinterested in idle conversation, the Giants' 23-year-old left-hander turns into a focused sharpshooter when the stakes are highest. He becomes incredibly articulate with a baseball in his large left hand.
Bumgarner showed it in 2010, when he blew away Texas for eight shutout innings in World Series Game 4, one night before the big San Francisco celebration, and he did it again in Game 2 of the 2012 Fall Classic on Thursday night at AT&T Park.
Turning away the Tigers on two hits across seven shutout innings in a 2-0 victory, Bumgarner sent the Giants to Detroit with a two-game cushion. He probably was even more impressive than he'd been two years earlier in Texas, given the circumstances coming into his sixth career postseason start.
Bumgarner had experienced some rough treatment by the Reds and Cardinals, and all the doubts and negative emotions something like that can bring to any pitcher, let alone one so young.
"I went into the seventh inning instead of getting took out in the third," Bumgarner said, evoking laughter when asked how this start differed from the previous two.
Mad about MadBum
In a more serious tone, he added, "I think the only difference was being able to make pitches. I hadn't been able to do that this postseason, and tonight ... Buster [Posey] caught a great game, [and the] defense did great. [The Tigers] hit some balls hard, and [the defense] just happened to be in the right spot."
Bumgarner also happened to ring up eight strikeouts, two more than he'd delivered in those two previous outings combined. He walked two hitters and hit one with a pitch.
What is it about the Fall Classic stage -- 15 innings, 0.00 ERA, 2-0 -- that lifts Bumgarner?
He said he didn't draw on his gem against the Rangers in any way.
"You know, this is a different year," Bumgarner said. "Obviously, I've been struggling a little bit. I wanted to go out there and try to pitch well for our guys and the fans, and that's all I was thinking about, just doing what I needed to do and make pitches. That's it, really."
Posey, another man not known for his long-winded speeches, offered a little insight into Bumgarner's makeup.
"His ability to stay calm helps," Posey said. "He doesn't get caught up in the excitement, but he feels it as well. That's a good combination."
A lethal combination for Detroit's notorious band of sluggers was the blend of fastballs, sliders and curves the 6-foot-5 Bumgarner sent their way.
On the heels of those disappointing starts against Cincinnati and St. Louis in the National League playoffs -- eight total innings, 10 runs on 15 hits, two losses -- Bumgarner went under the hood with pitching coach Dave Righetti and fixed some things.
The pitcher didn't want to be specific about the adjustments he and "Rags" made, but San Francisco manager Bruce Bochy saw a more compact, simpler delivery and commended both men for resolving the issues.
Bumgarner was on his game from the get-go, joining Hall of Famers Christy Mathewson and Carl Hubbell as the only Giants in franchise history to strike out the first two hitters in a World Series game.
Austin Jackson (looking) and Omar Infante (swinging) went down on wicked sliders. Miguel Cabrera's groundout wrapped a perfect beginning.
"I thought the first inning would be a critical inning for him, for his confidence, also just to see where he was at," Bochy said. "Really, I mean, what a job he did. He's worked on some things, and Rags -- Dave Righetti, our pitching coach -- did a great job getting him back on track. He had great poise out there with a great delivery, and he stayed right on for seven innings."
Bumgarner, who was 16-11 with a 3.37 ERA in 32 regular-season starts, got a 10-day break after losing Game 1 of the NL Championship Series at home against the Cards. Bochy skipped Bumgarner next time around in that series but came back to him vs. the Tigers with the belief that he'd rediscover what was missing in those bullpen sessions with Righetti, a lefty of renown in his day.
"He's done such a great job for us," Bochy said, referring to Bumgarner. "I really thought he needed a break, and I thought he benefited from it -- getting some rest, both mentally and physically. He went out there and pitched like we know he can."
Doug Fister, forging on after taking a Gregor Blanco line drive off the back of his head in the second inning, matched Bumgarner zero for zero before San Francisco broke through with runs in the seventh and eighth innings.
Bumgarner humbly referenced help from his friends in the second.
After Prince Fielder took a pitch off the arm leading off the second, Delmon Young hit a shot past third base, down the left-field line. Bochy thought it was a Tigers run when he saw the ball carom off the wall, but Blanco, Marco Scutaro and Posey had other ideas.
As Fielder rumbled around the bases, intent on scoring, Blanco adeptly backhanded the ball and unleashed a bullet over Brandon Crawford to safety cutoff man Scutaro. The second baseman, a natural shortstop, wheeled and gave Posey a perfect peg he could handle and erase Fielder with a swipe tag.
Fielder disputed the call, but Detroit manager Jim Leyland agreed it was correct.
"Yeah, that was huge," Bumgarner said. "I think that might have been a momentum shifter for me, because I had some trouble in the second, third, fourth innings the last couple starts. The defense bailed me out there. It was a huge play, got me excited. [I was] happy we were able to get out of it unscathed."
Bumgarner picked off Infante in the fourth after a leadoff single, and walks to Jackson in the fifth and Cabrera in the sixth went nowhere.
The last six Tigers hitters were dispatched by Santiago Casilla and Sergio Romo, and the Giants were on their way to Motown, two happy endings away from a second championship in three seasons.
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.