[Az.Ump]

I only have the 2005 books. The L.L. green book covers both softball and baseball as does the RIM. The L.L. softball book covers just softball but leaves out many of the comments and explanations. L.L. softball treats obstruction the same in softball as it does baseball. The rule I am told is written like the NCAA men’s rule. It has both type "A" and "B" with automatic awards for type A. If the defensive player blocks the base prior to the throw then they must receive the throw prior to the obstruction. If they set up not blocking the base and the throw takes them there than we have possible train wreck live ball play on. There is still umpire judgment as to if the player had a reasonable chance to glove the ball.


From the 2005 book.

OBSTRUCTION is the act of a fielder who, while not in possession of the ball, impedes the progress of any runner. A fake tag is considered obstruction. (NOTE: Obstruction shall be called on a defensive player who blocks off a base, base line or home plate from a base runner while not in possession of the ball.)
Author's Note:
The November 2002 Fair Ball had the following comment:
Comments – Examples of obstruction: The first basemen using their foot or sometimes dropping down and using their leg from the knee down to block the runner's dive/step back into first base on a pickoff throw; or the shortstop without the ball coming in behind the runner leading off second base and blocking the runner's path back to the base on pickoff throws; the third basemen standing in the base line watching the play develop and making the base runner go around to touch third base. All are obstruction because all would occur prior to the defensive player catching the ball, and many times the runner has no opportunity to get back to the base or get to a base. The defensive player (after being contacted by the runner who was attempting to return to the base) would then catch the ball and apply the tag.
The play where the throw takes a fielder into the path of a runner is still incidental contact, i.e. a train wreck, as it always has been. If a throw takes a defensive player (in a legitimate attempt to catch the throw) into a baseline or in front of a base/plate and there is contact with the base runner, this should be deemed incidental contact (as it always has been) and would only be obstruction if the umpire determined the contact was intentional.
The defensive players should be taught that without the ball they must stay out of the baseline and once they have made the catch they may now go into the baseline to apply (make) the tag. Instead of how it has been in the past, where they are taught to block the base (plate), and then catch the ball and apply (make) the tag.
This is how they (L.L.) teach it at their schools for both baseball and softball.

Paul B.