Hotbox is a baseball drill or mini-game that can be played with three or more players and two to four bases.
At any time, a runner may attempt to run to the next or previous base.
Errors usually happen as well, where the fielders must contend as the runners scramble to earn additional bases.
Some players may choose to devise a penalty for hitting a runner with a ball, such as a deduction in the fielder's own score.
If it is too difficult for runners to advance safely, the bases can be spaced closer together to shift the balance; conversely, bases further apart give the fielders an advantage (assuming they can throw well).