Baseball Glossary
tag up
After a fly ball is caught, a baserunner must touch (or "retouch") their current base before advancing. The runner waits on the base, watches for the catch, then runs to the next base. If they leave early and the defense appeals, the runner is out.
double play
A defensive play where two outs are recorded on a single batted ball. The most common is the 6-4-3 (shortstop to 2nd baseman to 1st baseman) on a ground ball with a runner on 1st.
force out
When a baserunner is forced to advance because the batter becomes a runner, the defense can get an out by touching the base the runner is forced to, rather than tagging the runner. Removes the need for a tag play.
sacrifice fly
A fly ball caught by an outfielder that allows a runner on 3rd to tag up and score. The batter is out, but the run scores. It doesn't count as an at-bat for the hitter.
sacrifice bunt
A bunt where the batter intentionally gives themselves up (gets out) to advance a runner into scoring position. The batter squares around and softly bunts the ball, forcing the defense to field it while the runner advances.
ground ball
A batted ball that rolls or bounces along the ground in the infield. Fielders must field it cleanly and throw to a base for the out. Ground balls with runners on base often lead to force plays or double plays.
fly ball
A batted ball hit high into the air. If caught by a fielder before it touches the ground, the batter is out. Runners on base can tag up and advance after the catch.
line drive
A batted ball hit hard and on a relatively straight trajectory. Line drives are dangerous for baserunners because they can be caught quickly, leading to easy double plays if runners are off their bases.
wild pitch
A pitch so far outside the strike zone that the catcher cannot catch or block it, allowing baserunners to advance. Scored as the pitcher's fault (unlike a passed ball, which is the catcher's fault).
passed ball
A pitch that the catcher should have caught or blocked but didn't, allowing runners to advance. Unlike a wild pitch, a passed ball is scored as the catcher's error.
cutoff man
An infielder who positions themselves between an outfielder and the target base to receive and redirect throws. The cutoff man can let the throw go through, cut it off and throw to another base, or hold the ball. Proper cutoff alignment is critical for preventing extra bases.
rundown
When a baserunner is caught between two bases and the defense throws the ball back and forth to tag them out. The goal for the defense is to use as few throws as possible — each throw is a chance for an error.
go halfway
A baserunning strategy on fly balls where the runner advances to a point roughly halfway between their current base and the next one. If the ball drops, they can easily advance. If caught, they can retreat safely. Used on medium-depth fly balls where tagging up isn't ideal.
on contact
A baserunning strategy where the runner takes off running as soon as the ball is hit (on contact with the bat), regardless of where it goes. Used on ground balls to avoid double plays and with 2 outs when you run on anything.
bunt
A batting technique where the hitter holds the bat still and lets the ball hit it softly, placing it in the infield. Used for sacrifice bunts (advance runners), bunt-for-hits (beat out a throw), or squeeze plays (score a runner from 3rd).
infield fly
With runners on 1st and 2nd (or bases loaded) and less than 2 outs, a fair fly ball that an infielder can catch with ordinary effort results in the batter being automatically out. This rule prevents the defense from intentionally dropping the ball to get a double or triple play.