How Baseball Tag-Ups Work Explainer
A runner must tag up when a fair or foul fly ball is caught before touching the ground. The runner returns to the occupied base, waits until a fielder first touches the ball, and may then try to advance. Leaving before first contact creates an appealable baserunning violation.
The runner does not have to wait until the catch is fully completed. The legal release point is the fielder's first touch, which matters on bobbled catches. A quick runner may break for the next base while the ball is still moving between a glove and a fielder's body.
An early departure is not called automatically. The defense must appeal before the next pitch or play by clearly identifying the runner and missed retouch. If the umpire upholds the appeal, the runner is out; on a third out, a run may be erased depending on timing.
Tagging up is a risk-and-reward decision. Coaches weigh the catch location, the fielder's arm, the runner's speed, and the game situation. Viewers should watch the base at first touch, then follow the throw and listen for any appeal after the play appears to end.
As soon as a fielder first touches the fly ball, even if the catch is completed a moment later.
No. The defense must make a valid appeal before the next pitch or play.
Yes. A caught foul fly is live, and runners must retouch before advancing.
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