SCOTTSDALE, Ariz. — The 232 batters who struck out 485 times against Madison Bumgarner over the past two seasons should be overjoyed to hear him declare that his mechanics have been off-kilter the whole time.

“I know I’m being a perfectionist,” Bumgarner said, “but I haven’t had it how I’ve wanted it the last couple of years. It’s funny how hard that is to dial in, but I’m not that far off.”

If this was Bumgarner not dialed in, heaven help hitters when he figures it out. In 2015, he had a 2.93 ERA and 234 strikeouts in 2181/3 innings. In 2016, the year he turned 27, he topped that.

Bumgarner had the best ERA of his career at 2.74. He also had regular-season career highs in innings (2262/3) and more strikeouts (251) than any other left-hander in Giants history. As an encore, he pitched his second career shutout in a National League wild-card game.

He dominated last year despite a 1.3-mph drop in average fastball velocity, from 92 to 90.7, while throwing a league-leading 3,571 regular-season pitches.

Sound mechanics or not, Bumgarner has found his sweet spot.

“He’s at the ultimate stage where your experience and your physical abilities line up,” said Craig Counsell, who faced Bumgarner as a hitter in 2010, then lost twice to the big North Carolinian last season as the Milwaukee Brewers’ manager.

“I think he’s been in that spot the last couple of years, the prime, so to speak.”

The question is, how long will Bumgarner reside there?

Giants management and ownership will have to gaze into a crystal ball and ask themselves that question before they agree to what surely would be the biggest pitching contract in team history.

The team’s hopes of returning to the World Series hinge on the answer as well.

The man has been consistent.

Bumgarner has pitched at least 200 innings and struck out at least 190 in all six of his full big-league seasons. Only one other pitcher, Cole Hamels, has accomplished that over the same period. No other San Francisco Giant ever had those numbers over six consecutive seasons.

And yet, consistency does not equal sameness.

Bumgarner is not the pitcher he was in 2010, when he arrived in San Francisco for good at 20, then later that year, at 21, pitched eight shutout innings at Texas in Game 4 of the World Series.

Nor will Bumgarner likely be the same pitcher seven years hence when he reaches his mid-30s.

In his early seasons, he often relied on the cutter as his “out” pitch. But more pitchers throw it now, which means hitters see it more, forcing Bumgarner to attack them with a different mix of pitches.

Bumgarner also recalled that as a rookie, he could not throw a fastball away to save his life.

Catcher Buster Posey said the biggest difference between Bumgarner in 2011 and Bumgarner today is how quickly he adjusts when hitters are on to him. He recognizes swings better, allowing him to change his game plan midway through a plate appearance, not later in the game.

Bumgarner’s success also derives from his understanding that the pitcher controls the action.

“Hitting is hard,” Bumgarner said. “You can get away with a lot, but sometimes it feels pretty dang tough to get these guys out. But if your stuff is good and your body feels good and you’ve got command of your pitches, you’re usually going to be all right.”

Which might explain why Bumgarner could have his best year when his mechanics were off and his velocity down.

“Everybody can get too caught up in mechanics,” he said. “It doesn’t matter how hard you throw or where you throw it. We get paid to get outs.”

Back to Gallery Madison Bumgarner, his Giants future and the pursuit of... 2 1 of 2 Photo: Chris Carlson, Associated Press 2 of 2 Photo: Chris Carlson, Associated Press



Bumgarner understands that good health is a big reason for his success — “That’s a pretty good blessing there” — and no matter how many strikeouts he racks up or rings he accumulates, he will have to adapt in the weight room when he gets older. He has paid attention to how current and former Giants pitchers Matt Cain, Tim Hudson and Jake Peavy train.

Bumgarner is built as tough as the trucks he hawks on TV, but time has a way of neutralizing the physical gifts that nature endows.

“I think he understands that,” Posey said. “He’s very aware of what his body is doing.”

Posey also has a clear view into Bumgarner’s mind after catching him all these years and sounds confident that the four-time All-Star will have the physical and mental tools to adapt as he ages.

“He’s such a perfectionist, it’s almost inevitable for his stuff to get better because he pays attention to the details so much,” Posey said, conjuring the same word that Bumgarner used to describe himself.

Those close to Bumgarner have told him he need not be perfect to win, that perfectionism can be a curse when failure arises and an athlete needs to make incremental adjustment after incremental adjustment to regain success.

Woe is the coach, teammate, friend or relative who tells Bumgarner to relax and not try so hard when things go awry.

“I cannot stand that,” Bumgarner said. “You want me to try less? I don’t understand it. That’s not my deal there.

“I don’t know if anybody will ever be as good as they picture themselves being. But if you strive for that, that’s about all you can do, really.”

Henry Schulman is a San Francisco Chronicle staff writer. Email: hschulman@sfchronicle.com Twitter: @hankschulman

A heavy workload

A look at Madison Bumgarner’s career statistics:

Regular season Postseason Year Innings ERA SO Innings ERA SO 2009 10 1.80 10 -- -- -- 2010 111 3.00 86 202/3 2.18 18 2011 2042/3 3.21 191 -- -- -- 2012 2081/3 3.37 191 15 6.00 14 2013 2011/3 2.77 199 -- -- -- 2014 2171/3 2.98 219 522/3 1.03 45 2015 2181/3 2.93 234 -- -- -- 2016 2262/3 2.74 251 14 1.93 10 Career 1,3972/3 2.99 1,381 1021/3 2.11 87