OBR 6.01(j)

The slide rule at second base

Breaking up a double play now requires a bona fide slide: hit the ground before the base, stay within reach of it, and make no attempt to change path or roll into the fielder. Violate it and both the runner and the batter are out.

Key points

Four tests: slide begins before the base, the runner can reach the base with a hand or foot, he can stay on it, and he does not change pathway to initiate contact.
A legal slide that makes contact is fine — contact alone is not interference.
Violation: runner out AND batter-runner out, and other runners return to their original bases.
Adopted in 2016 after high-profile takeout injuries; fielders still must make a genuine play on the ball.

In a game

Runner slides past second with his spikes up into the shortstop's thigh as the relay goes to first.

Ruling · No bona fide slide — both runners are out, the double play is automatic, and any run that crossed comes back.

Why it moves the scoreboard

One illegal slide converts a fielder's-choice inning into a two-out swing and wipes advancing runners back to their starting bases.