There are nine innings, during half of each of which one team plays offense and the other plays defense. They switch for the remaining half of each inning. Th

There are nine innings, during half of each of which one team plays offense and the other plays defense. They switch for the remaining half of each inning. The offense is permitted three "outs" in their half of each inning (after which the teams switch roles, or the next inning commences). There are four bases, the first three of which may be occupied by a member of the offense. Bases are ordered. Players may advance directly from one base to the next by "stealing". This comes at the risk of an out, which results in losing occupation of a base entirely. A player which reaches the fourth base scores a "run" for the offense and no longer occupies a base. Runs (and only runs) count toward the final score. One player from offense is always "at bat". That player has a chance to occupy a base (not necessarily the first); failure to do so results in an out. During this process, the other base occupants may (be forced to) advance bases, possibly scoring runs or losing bases and gaining outs in the process. (The particulars of this are not relevant to the article, but there is a fun story about the process here [1].) Rather than permit the player at bat the chance to advance potentially several bases, the defense can "walk" the batter by granting them uncontested occupation of first base. Similarly, rather than permit the defense to prevent any base advancement, the player at bat can choose a "sacrificial bunt" ("sac" bunt) which, properly executed, nearly guarantees that players currently occupying bases advance one base (or even score), while the player at bat (and only that player) is called out (and thus does not advance). SPOILER ALERT. This action is key to the plot in a particular episode of Deep Space 9 [2]. [1] http://www.espn.com/mlb/story/_/id/20294816/skunk-outfield-how-most-epic-trick-play-history-broke-baseball http://www.espn.com/mlb/story/_/id/20294816/skunk-outfield-h... [2] http://memory-alpha.wikia.com/wiki/Take_Me_Out_to_the_Holosuite_(episode) http://memory-alpha.wikia.com/wiki/Take_Me_Out_to_the_Holosu...