The problem I have with that interpretation is that "emminent play" would equate to the old rule of several years ago that allowed the defense to block a base if they were "about to receive" a throw.
Under the newer, current rule, the fact that a play is being made should have no relevence on the obstruction call.
Obstruction now requires two separate and distinct elements. One, a defender blocking the runners path without the ball and, two, the runner altering her path as a result of that blocking.
Either you have both of those elements on the play and you have obstruction, or you have one or neither and no obstruction.
"Emminent play" is a non-factor when making this call (unless you are calling an NCAA game, where the "about to receive" clause is still on the books).
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Carolyn (RobeyWarren):
Do you have access to a copy of any special rules that your league has adopted? They may have possibly added a "must slide" rule for the league.
Strictly "by-the-book" ASA rules do not require a runner to slide. She can slide OR avoid the fielder. Veering off, slowing down or stopping would be examples of safe- and legal- ways for a runner to avoid contact with a fielder.
"Must slide" rules are misguided attempts to protect fielders that increase the likelihood of injury to a runner. The basic rules already offer the runner several safe ways to avoid contact without forcing her to perform a dangerous manuveur tha she may or may not be comfortable with.