When a manager wants to substitute one player for another, he informs the umpire of his intended substitution and the umpire marks the change on his copy of the lineup card. After a player from the starting lineup is replaced, he is done for the day and cannot re-enter, though some leagues or levels allow re-entry.
For the purposes of this lesson on The Batter, we will focus on offensive substitutions. These can take the form of either a “pinch hitter” or a “pinch runner.” Unlike defensive substitutions where multiple players can enter at one time, offensive substitutions must be made one at a time.
A manager can make an offensive substitution when a batter he wants to replace is due up in the batting order. This type of substitution is referred to as pinch hitting. The incoming pinch hitter must remain in the same batting order slot as the batter he replaced.
The manager can also choose to make an offensive substitution after a batter has successfully reached base. In this case, the incoming player will replace the previous runner at the base he was occupying. Much like the pinch hitter, the incoming pinch runner will replace the replaced player’s respective spot in the batting order for the rest of the game (unless he also becomes replaced).