Obstruction at First

[jicecone]

Baseball Rule Differences does a pretty good job of
explaining this.

The Rule books also define obstruction. The fielder must be in the act of fielding or receiving the ball. Well this can't begin until F1 has released the ball. At that point the fielder is in the act of receiving. I thought some codes have also used the words "in the immeadite act of receiving the ball".

Under OBR 7.06 and the Obstruction def, the umpire has to make the determination of whether the fielder was in the "act of fielding". Certainly, a catcher receiving a throw from the outfield is different than F3 receiving a throw from the F1.

Unless the code specifically states that the fielder must have "possesion of the ball", or something similar, your best call is, OUT.