| Back Door Slide | A runner slides into the base behind the basepath, almost sliding past the base and then reaching over to the touch the base as he goes by. The idea behind the strategy is to make it more difficult for the fielder to tag him out by having to reach a bit further back. |
| Bang Bang Play | A close fast play at a base |
| Base Hit | Batter reaches base safely on a fair ball hit |
| Base line | A chalked or imaginary line between bases that the runner has priority for moving between bases. The runner is allowed a little bit of leeway either way or else he will be considered outside his base line. |
| Base on Balls (BB) | The longer name for a walk. When the batter receives 4 balls he can take first base. |
| Bat Flip | After a home run, the batter may exaggerate the dropping of his bat with a bat flip which can be compared to touchdown dances or goal celebrations. The Bat Flip can be controversial and offensive to some players |
| Battery | The Pitcher and Catcher together are known as "The Battery" which symoblizes that they power the pace of the game |
| Batting Practice (BP) | Before each game, batters will face live pitching to prepare for the upcoming game. BP takes place on the field and is thrown by a coach behind a cage, usually throwing 70mph to simulate reaction time of an opposing pitcher on the mound |
| Batting Stance | The repeatable stance used by a batter when idle and waiting for pitcher to begin his windup |
| Bench player | A reserve player on active roster who typically comes into the game to pinch hit, pinch run or as a defensive replacement with the occasional spot start |
| Bleachers | The grandstands beyond the outfield fences |
| Bloop | A batted ball that is between a liner and a fly ball that is hit relatively softly with some loft that often lands in between outfield and infield |
| Blown Save | A relief pitcher who enters the game with a save opportunity but leaves the game with the lead lost will be given a blown save. |
| Blue | A nicknamed used to summon an umpire |
| Booted ball | Usually refers to a ball hit to a fielder that bounces off the fielder and away from him. The result is usually scored as an error since the insinuation is that it was a fieldable ball. |
| Brushback Pitch | A pitch thrown by the pitcher with the intention of moving the batter off the plate. |
| Bullet | A hard line-drive |
| Bullpen | Can refer to the group of relievers or the physical space occupied by the relievers beyond the outfield fence. |
| Bump, The | Slang for the pitcher's mound |
| Bunt | A batter will square into a bunt position (one and halfway up the bat and a concentrated stance) in an effort to deaden the pitched ball so the ball rolls slowly into the infield, forcing the fielders to charge and make a challening play. A bunt is often used as a sacrifice where a team will concede an out to move a runner up a base. It can be used by a batter strategically to surprise a shifted infield. It can be used by a speedy runner who is trying to get on base but most often it is used by a pitcher who is simply trying to do something positive instead of an eventual likely strikeout. |
| Bust | A highly touted player who does not live up to experts expectations which may the fault of the player or those who held the expectations |
| 21 record(s) |