I`m Chinese and i don`t konw what the "Home runner" exactly means,who can tell me :)?

See here (http://en.wikipedia.org/wiki/Home_run, set to Chinese if it exists :p)

In baseball, a home run (abbreviated HR) is scored when the ball is hit in such a way that the batter is able to circle all the bases in one play without any errors being committed by the defensive team in the process. In modern baseball, the feat is typically achieved by hitting the ball over the outfield fence between the foul poles (or making contact with either foul pole) without first touching the ground[1], resulting in an automatic home run. There is also the "inside-the-park" home run, increasingly rare in modern baseball, where the batter circles the bases while the baseball is in play on the field.

When a home run is scored, the batter is also credited with a hit and a run scored, and an RBI for each runner that scores, including himself. Likewise, the pitcher is recorded as having given up a hit, a run for each runner that scores including the batter, and an earned run each for the batter and for all baserunners who did not initially reach base on error, except for the runs scored by any runners who reached base while facing an earlier pitcher are charged to that pitcher.

Home runs are among the most popular aspects of baseball and, as a result, prolific home run hitters are usually the most popular among fans and consequently the highest paid by teams, hence the old saying, variously attributed to slugger Ralph Kiner, or to a teammate talking about Kiner, "Home run hitters drive Cadillacs, and singles hitters drive Fords."

In Worms Reloaded the baseball bat hints at this when you hit a worm into the water (replacing the outfield fence) by playing the "home run theme" or however you call that. It's a simple gag :)