Easy, though a little surprising.
"If I had to pick one side, I would be a right-handed hitter," said Headley, who struggled from the right side a year ago for reasons he still can't explain.
Headley, who took part in the Padres' first full-squad workout Saturday under unusually dark skies in Peoria, hit a mere .217 in 2010 as a right-handed batter. That was the fifth-lowest average against left-handed pitching among National League players who finished with at least 180 at-bats.
Headley is vowing to be better because, well, he's done it before.
"I fully expect to bounce back and have a much better year from that side," Headley said.
After all, Headley is a natural right-handed hitter who had success hitting right-handed climbing up the Minor League ladder to reach the big leagues. He was a .301 hitter in the Minors, including a .274 mark against lefties.
Heck, in his first 302 Major League at-bats from the right side, from his promotion in 2007 through '09, Headley hit .255 against lefties with eight home runs. That's why he's still trying to come up for an answer as to why he struggled so mightily last year.
"Historically, during my entire baseball career, I've always been a good right-handed hitter," Headley said. "But sometimes you just go through things you can't explain. That's just how it happened, and I can't worry about it now."
The Padres are expecting better things from Headley, who finished the season at .264 with 11 home runs and 58 RBIs. Even though the team plans on using newcomer Jorge Cantu some at third base to spell Headley -- something it struggled to do a year ago -- San Diego certainly hasn't given up on Headley as a right-handed hitter, manager Bud Black said.
"He's a good baseball player," Black said. "He's going to have a good year."
Headley worked on his mechanics from the right side during the season until August when he found something that worked for him, something he feels he can carry into this year.
"Last year, toward the end of the year, I went to a toe-tap -- kind of a stride back, stride forward, stride. It gave me a lot more timing. I had more success at the end of the year," said Headley, who hit .296 in his final 54 at-bats against lefties.
"Also, I wanted to kind of shorten my stride. Sometimes I get too wide. I'm trying to stay a little narrower, not so much in my stance but when I'm finishing in my stride. I think it is going to help me."
To be clear, Headley isn't expecting to hit .300 from the right side -- though, of course, he wouldn't mind it. He just wants to be proficient enough so there isn't a dramatic split between hitting right-handed and left-handed.
"If I can be consistent from that side, have good swings consistently, the numbers will be fine," Headley said. "If I go back and look at my year last year, and if I could have gotten my right-hand numbers to be even 30 points less than my left-hand numbers [.285], I would have had a pretty good year.
"I'm trying to get that swing to back to where I know it can be."