Pinch Hitters

So Taguchi was pinch hitting when he singled over the outfielder's to get an RBI and put the Cardinals ahead of the Cincinnati Reds on 6/5.

Pinch Hitters are subsitutes in the line-up (list of active players, their positions, and their batting order) while a team is batting (on the offensive). Usually, a pinch hitter is subbed in for a pitcher, but cna be anyone that will be replaced next time the team takes the field. You can't bat unless you are in the line up, but you can subsitute players. For example, pitchers are notoriously bad hitters, so Taguchi was subbed in to bat, then the next time out, a different pitcher was subbed in for Taguchi.

Ayway, the outfield came in close because they expected Taguchi to hit it just over the infield. He hit it over their heads and got on base, but also advanced a runner home, an RBI - Run Batted In. That means he gets credit for assisting the runner to score.