B/R between HP and 1B

[SanDiegoSteve]

FED: A batter-runner may legally retreat toward the plate to avoid a tag unless he touches or runs beyond the plate, when he will be called out. The ball remains alive. 8-1-1a.

Official Interpretation from Rumble: When a batter is retreating toward the plate, the umpire will always call obstruction if B1 "collides" with the catcher (National Federation News #17, 3/94).

NCAA: Same as FED (7-11p AR 3) EXCEPT: The rule does not mention the status of the ball, and no official interpretation exists to deal with obstruction.

OBR: Point not covered in Rule Book. See above post by umpyre007 for the PBUC interpretation.

Also: Official Interpretation from PBUC manual: When a batter is retreating toward the plate, the umpire rules obstruction only when he judges it is intentional (4.31 - 1).