It’s not the toughest home run park in the majors — over time, that’s still proven to be San Francisco’s AT&T Park — but Target Field has made things pretty tough on power hitters since it first opened in 2010.

How much bearing will that have on Monday’s Home Run Derby? Not much, said ESPN analyst John Kruk.

“Is it a little tougher to hit it there than it was in Arizona [three] years ago or some other ballparks that are smaller? Yes,” Kruk said. “But these guys [in batting practice] make most ballparks look like a Little League field.”

Power hitters at Target Field have learned to pull balls down the foul lines. It’s 339 feet down the left-field line and 328 feet down the right-field line. But the alleys aren’t nearly as forgiving.

It’s 377 feet to left-center, where, for comparison, Baltimore’s Camden Yards is 364 feet. And then there’s right-center. As Nick Swisher said after a game at Target Field in 2011, “It’s 403 [feet to the right corner of the center-field fence], and there’s a 30-foot wall [actually 23-foot]. You’ve got to be a grown man to hit it out of there. I’ve got to go down the lines.”

According to ESPN’s Park Factors, which compares the rate at which players hit home runs from ballpark to ballpark, Target Field was the majors’ toughest home run park in 2010. It climbed to 14th toughest in 2012 but sank to 27th last year before rising to ninth this year.

“Left field, the ball flies and can get out of there pretty quick,” Twins manager Ron Gardenhire said. “Righthanders definitely have the advantage. Lefthanders, if you’re pulling it down the line, it goes.”

Justin Morneau is the only lefthanded hitter in the field. But at least he knows the park.

JOE CHRISTENSEN