deck

In baseball, on deck refers to being next in line to bat. In a professional game, the batter who is on deck traditionally waits in a location in the foul territory called the on deck circle.
Being on deck only guarantees the batter will get a chance to bat in the inning if there are fewer than two outs, and the number of outs plus the number of baserunners adds up to fewer than three because a double or triple play could occur. Additionally, the manager reserves the right to pull the on-deck hitter for a substitute at his discretion.
The player next in line to bat behind the on deck batter is referred to as being in-the-hole.

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