Known for using a hard upper-80s mph slider as his go-to breaking ball, Bumgarner interchangeably mixed in his new-look curveball to keep the Astros guessing, holding them to one run on two hits in the Giants' 5-1 win.
Bumgarner, 22, worked with veteran reliever Jeremy Affeldt to make the adjustment to keep his hand on top of the ball more and have a bigger follow-through towards his right leg on his curveball, which exhibits both Bumgarner's will to adjust his pitches and Affeldt's role as a source of advice and mentorship to his fellow southpaw teammate.
"I actually was just watching and talking to Affeldt, he has a really good curveball," Bumgarner said. "We've been working on some stuff, and I made a little adjustment, and it made it a whole lot better."
Bumgarner is coming off a first half in which he picked up right where he left off from his solid 2011 season, his first full year as a starter. After going 13-13 with a 3.21 ERA in 204 2/3 innings last year, Bumgarner is currently 11-5 with a 3.15 ERA, and has emerged as one of the most promising young left-handers in the game.
And even with his early success, teammates and coaches have noticed the former 2007 first-round Draft pick's desire to add to his repertoire with better, improved pitches and mechanics.
"In this game, it will keep you fresh," pitching coach Dave Righetti said. "You can always say, 'Well, I'm going to do my thing and stay the course, and when stuff goes bad, I'm just going to be that guy and stay consistent.' And then there are guys who say, 'Well, I'm going to tweak it and get a little bit better.'
"You have to find a happy medium, something that's comfortable for you. And in Madison's case, he's always trying to tweak it and get a little bit better every time. It's a conscious effort for him to get better and for him to stay on top of things."
Outside of the coaching staff, the 11-year veteran Affeldt has been a source of information for Bumgarner. Bumgarner sat in the bullpen with Affeldt and other relievers during the series against the Pirates before the All-Star break in order to pick their brains on their respective breaking balls.
"They talk all the time, they've been talking since he came up," Righetti said of Bumgarner and Affeldt. "Being left-handed, Jeremy has always been there to help and offer encouragement."
Coming up through the Kansas City Royals organization to make his debut in 2002, Affeldt spent the better part of seven years battling to be a regular starter before fully embracing his niche as a lefty setup man in the bullpen when he signed with the Giants in '09.
"When I try to give him advice, I don't try and necessarily give advice from my successes, but from my failures," Affeldt said. "If I could have gone back earlier in my career and did things differently, these are the things I would have done. I didn't learn a sinker until seven years into the big leagues. I would have learned a sinker way earlier, and that might have kept me in the rotation a lot longer."
Affeldt pointed to Bumgarner's sound mechanics and his willingness to adjust his approach as being conducive to him picking up different pitches later in his career, which Affeldt has encouraged him to do.
"It's just going to make him better," Affeldt said. "There are other pitches that he'll want to develop later in his career like a sinker to complement his cutter, and eventually I think he's going to need to have one of those to keep guys guessing on that side of the plate.
"For me, I talk about looking back what I wish I would have done, and I already see him doing those things."
Righetti describes Affeldt as coming across as a "clown and goofball" at times, but said Affeldt has always held the respect of his teammates as a valuable source of advice and encouragement.
"He's a veteran guy who has been through the wars, so to speak," Righetti said. "We tend to get a lot of young guys, so it's always great to have a guy like Jeremy."
Bumgarner has impressed Affeldt with his understanding of his pitching mechanics and his meticulous nature with his pitching preparations, which Affeldt said he didn't develop until later in his career.
"Conviction is huge when it comes to pitching," Affeldt said. "I didn't have that when I was younger. Somebody would ask me why I would throw with a higher arm slot when I was younger, and I didn't know. I finally had to change my arm slot to be a little bit lower, and it's helped me. Now I know why it is where it is, so when I'm off out there or I'm not mechanically sound, I can go back to what makes sense and what works. And he's already doing that, and that's not something that comes along at an early age."
And Affeldt predicts even bigger successes for Bumgarner, saying that if he maintains his desire to improve and adjust, Affeldt has "no doubt" that the recent recipient of a five-year, $35 million extension will be a Cy Young Award winner in the near future.
"He has an opportunity to be a part of something really, really great in his career," Affeldt said. "He doesn't get complacent, he always wants to keep developing, always wanting to learn."
Jay Lee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.