The Rules of Baseball : How to Tag Up in Baseball

[karandipsohal]

What is the purpose of tagging up?

[davidemerling]

One of the thing some coaches teach (incorrectly) is that the runner at third should not watch the ball and wait for the coach to say "Go!" That is poor instruction. The runner can get a much better jump by watching the ball himself instead of waiting for the coach to relay it to him. Plus, there is less of a chance of leaving early or late when doing it this way. Sometimes third basemen like to block the runner's view. Technically, that is illegal, but it is seldom called by the umpire.

[baseballpitch100]

@davidemerling Yeah,it wouldn't be fair to the runner.