Checked Swing
alternatives: Check Swing, He Checked His Swing
Message Pitch
Pitch Count
Caught Stealing
Day Game After a Night Game
usually relevant for catchers, some of whom don't play the day game if it follows a night game in the same town.
Getaway Day
the game before the team travels away from a series when they're the visting team, or, for the home team, the day before they travel on the road.
Save Situation
The Wikipedia page on baseball saves has an outline of what a save situation is.
Sacrifice Situation
Usually when there is someone on first base and nobody out, where a batter might bunt the ball to move the runner over. Especially true if there's a runner on first and second and no outs.
Double Switch
Swinging Bunt
In Line For The Win
when a pitcher leaves the game and he's qualified for the stat called a "win". Could be shortened to ILFTW.
Humpback Liner (which is the name of a blog)
Loud Strikes
Batter's Eye
This is the name of my baseball pool team, so please don't call your band that.