[greymule]

PBUC 4.16:

"If the batter-runner drops his bat and the ball rolls against the bat in fair territory and, in the umpire's judgment, there was no intention to interfere with the course of the ball, the ball is alive and in play."

(It's apparently not automatically fair, though. If it goes foul, it's a foul ball. But if ball hits bat in foul territory, it's automatically foul.)

"If after hitting or bunting a fair ball, the batter's bat hits the ball a second time in fair territory, the batter is out and the ball is dead."

However, the Fed case book seems to allow "bat hits ball" as long as it's not intentional. (Ignore the case book's erroneous, misleading grammar: batter . . . hits the ball . . . and is either touched . . . and/or comes to rest. . . .):

2.9.1 Situation D: Batter unintentionally hits the ball a second time in (a) fair territory and is either touched by a fielder and/or comes to rest in fair territory; (b) foul territory and is either touched by a fielder and/or comes to rest in either fair or foul territory; or (c) fair territory and is either touched by a fielder and/or comes to rest in foul territory. Ruling: In (a) and (c), the ball is fair. In (b), the ball is foul.

Also note apparent agreement with PBUC:

2.16.1 Situation B: B1's bunt rolls up the first-base line where it hits B1's bat that was lying on the ground in fair territory. The ball deflects into foul territory. Is the ball fair or foul? Ruling: The ball is foul, provided the bat was not placed there intentionally. The bat is considered to be part of the playing field.

If I am reading the case book correctly, 2.9.1 Situation D part (c) says, "Bat hits fair ball, ball goes foul = FAIR ball," while 2.16.1 Situation B says, "Fair ball hits bat, ball goes foul = FOUL ball."

So in Fed, if moving bat contacts moving fair ball, the umpire has to determine whether bat or ball did the hitting, as fair/foul status hangs in the balance if the ball rolls into foul territory.