Posterior.
OBR 5.08(a)

Does the run count? Third-out timing

A run scores if the runner touches home before the third out is made — unless that third out is a force play, the batter-runner failing to reach first, or a preceding runner put out on appeal. In those three cases the run never counts, no matter the timing.

Key points
  • Third out is a force (including the batter at first): run never counts, even if the runner slid across first.
  • Third out is a tag or other non-force play: pure timing — run counts if the foot touched home before the tag was applied.
  • Successful appeal for leaving early on a fly is treated like a force for scoring purposes.
  • Umpires hold the call and scorekeepers apply 5.08(a) — this is the rule behind every 'the run counts!' argument.
In a game

Two outs, runner on third. Grounder to short; the runner breaks for home and slides across just before the throw to first retires the batter.

Ruling · No run. The third out was the batter-runner failing to reach first — a force for scoring purposes — so timing is irrelevant.

Two outs, runners on second and third. Ground ball deep in the hole; the runner from third scores, then the runner from second is tagged out at third.

Ruling · Run counts. The third out was a non-force tag, so it is a pure timing play — the run scored first.

Why it moves the scoreboard

Decides whether runs go on the board on the most chaotic plays in the game — double plays with a runner crossing home.

Related rules