"It's concentration. Like I say, I just see the ball and swing," Callaspo said.
Quite often this season, his first with the Royals, the contact swings have produced base hits. Up to Thursday, before a game against the Angels, Callaspo had a .350 average (14-for-40).
Strikeouts? Just two in 46 plate appearances.
"It's nice to have a guy with that type of ability to put the ball in play," Kansas City hitting coach Mike Barnett said.
Callaspo, obtained last winter from the Diamondbacks for pitcher Billy Buckner, has filled in at second base and shortstop. His arrival prompted speculation he might eventually succeed Mark Grudzielanek at second.
Callaspo is a 25-year-old switch-hitter from Maracay, Venezuela, where he grew up idolizing shortstop Omar Vizquel -- not that Callaspo hoped to match him defensively.
"No way -- he's the best," Callaspo said.
Callaspo, naturally right-handed, began switch-hitting at a young age.
"I started when I was like 10 or 12 years old," he said. "I wrote with both hands, and that's why."
Barnett believes Callaspo's quick hands are the secret to his ability to put the bat on the ball.
"The biggest thing is he tries to stay as short to the ball as he can and uses his hands," Barnett said. "He tries to keep his chest and shoulders out of the swing, which allows him to have a very short path to the ball. That allows him to let the ball travel more, and you're not going to get fooled as much."
Callaspo had a Minor League batting average of .321 in 717 games, mostly in the Angels organization. His split the last two seasons between the Minors and the D-backs.
Hitting .350 or anything close to it isn't easy for a part-time player in the Majors.
"It's difficult, because if you play every day, you can go 0-for-4 and say, 'OK, I can get it tomorrow,' but [playing] like this, you can't do that," he said.
"But it's OK; it's my job."
Callaspo is so versatile that last year he played at five different positions in the infield and outfield for Arizona. On Tuesday night, he replaced Tony Pena Jr., who is struggling with the bat, against the Angels and drew two walks. But Callaspo probably doesn't have the defensive range to replace Pena on an everyday basis.
Although he's played in 15 games, Callaspo has started just 10.
And despite an impressive average, his ability to make contact and his versatility, Royals manager Trey Hillman has no plans to make him a lineup regular.
"It's a possibility. But look at it objectively," Hillman said. "Is Callaspo going to fit in the middle of our lineup? Probably not. Could he fit up at the top, maybe hitting [second]? We've thought about one -- maybe.
"But the guys you've got slotted three through six, seven, those are the guys who have got to drive in runs, and we're just not doing it."
But if Hillman needs a contact hitter, he knows who to call: the guy with the most basic approach imaginable.
"Sometimes I just see the ball and swing -- that's all I do," Callaspo said.