When analysts examine long term situational batting, the best players often rise to the top. This list of the best hitters with runners in scoring position since the start of the 2008 season demonstrates that nicely. The hitters ranked one through six are among the best in the game, four of them having won a league MVP. Number seven, however, is David DeJesus of the A's, someone not thought of as the best in the game.
DeJesus over this time period hit .295 overall, but .327 with runners in scoring position. Looking at his batting heat maps, you can see the change in his approach.
With the chance for an RBI, David concentrates on the inside part of the plate, where he's more likely to pull the ball. What that does for him is increase his chances of hitting a line drive.
DeJesus hits over .700 on line drives, so pushing that rate up really helps him.
I do not wish to claim this is a real skill, however. David hit over .400 with runners in scoring position in 2008, and his batting average in the situation dropped every year since. He does seem to approach hitting differently in the situation, and that approach brought him to an area occupied by some of the game's best.