Thanks to the random vagaries of baseball, Robbie Grossman hadn’t batted with the bases loaded in more than a month when his turn came up in the second inning Saturday, a Twin standing on every base. Grossman fouled off a fastball from Royals righthander Dillon Gee, took a ball, then missed a curve, looking fooled. When Gee tried the curve again, except a few inches farther outside, Grossman let it go by.

Whoops. Kerwin Danley judged it had caught the corner of the plate, and the umpire’s right arm went up. Strike three. Inning over. Opportunity missed.

“Sometimes what makes him good hurts him,” manager Paul Molitor said of his fourth-year outfielder, who later hit a go-ahead solo home run in a 5-3 victory. “You like to see him put balls in play in those situations, but you also trust his eye, because that works out well.”

It often does, yes. On-base percentage is Grossman’s specialty, a talent he displayed in the minor leagues that he’s been able to bring with him to the Twins this season. With 44 walks in only 67 games, Grossman’s .389 on-base percentage not only leads the Twins, but it would rank fifth in the American League with a few dozen more plate appearances. Not bad for a guy hitting .270.

“The trend [spelled out in the book] ‘Moneyball,’ he’s one of the guys who fits that mode” of helping his team with lesser-appreciated talents, Molitor said. “Even with the lower batting average, his on-base percentage has remained rather lofty. He’s an attractive alternative when we’re doing things, changing the lineup a little bit or just changing up who gets to play.”

Grossman’s walk rate of 16.1 percent, in fact, ranks behind only Jim Thome’s 17.7 in 2011 as the highest by a Twin in the past quarter-century. “The idea is to get on base as many times as you can, that’s your one goal at the plate,” he said. “The only thing I pay attention to is on-base and how many runs I score. That’s really all that matters.”

It’s a batting style Grossman says was taught to him when he was first coming up in the minor league system of the Pirates, who drafted him in the sixth round in 2008. He never goes up to the plate looking to walk — but he’s determined to swing only at strikes, a big contrast to many hitters in this era.

“That was a really big emphasis for them — swinging at good pitches,” said Grossman, who took it to heart so well, he drew 104 walks in 134 games at Class A Bradenton in 2011. “I might have taken it further than most people do, but I have a pretty good idea what the strike zone is now. But sometimes it hurts me, and I have to be really careful. I have to be aware that I need to be more aggressive.”

That’s because he’s a statistical outlier in another category, too: called third strikes. Grossman has watched strike three go by 31 times this season, which ranks him 15th in the AL. Since the day he first became a Twin, May 20, only Baltimore’s Chris Davis has looked at more third strikes.

“I’ve always had a high walk rate, but it’s kind of a gift and a curse,” Grossman asid. “I’ve taken some pitches lately that have been close and haven’t gone my way. That’s the part of my game I need to get better at. There’s such a fine line.”

There is, and which side that pitch falls on depends upon the whims of an umpire. Grossman doesn’t blame umps for his strikeouts. “These guys aren’t perfect. They’re just trying to do the best job they can,” he said. “But sometimes on the 50-50 pitches, you take them one week, it’s a strike, and the next week it’s a ball.”

One adjustment he would like to make: Perhaps swing at more borderline pitches. Just to see what would happen.

“I have to tell myself, just because they’re not strikes doesn’t mean you can’t get hits off them. You can. Just look at Jose Altuve — he’s got a magic wand,” he said of his former Astros teammate. “And that’s something you have to keep reminding yourself — yes, you want a good pitch, but the borderline pitch, you can still hit it.”