[paulsonj72]

Originally Posted by Rita C

Assuming Official Baseball Rules: (I've highlighted the pertinent part.)

An INFIELD FLY is a fair fly ball (not including a line drive nor an attempted
bunt) which can be caught by an infielder with ordinary effort, when first and second, or first, second and third bases are occupied, before two are out. The pitcher, catcher and any outfielder who stations himself in the infield on the play shall be considered infielders for the purpose of this rule.

When it seems apparent that a batted ball will be an Infield Fly, the umpire shall immediately declare “Infield Fly” for the benefit of the runners. If the ball is near the baselines, the umpire shall declare “Infield Fly, if Fair.”

The ball is alive and runners may advance at the risk of the ball being caught, or retouch and advance after the ball is touched, the same as on any fly ball. If the hit becomes a foul ball, it is treated the same as any foul.

If a declared Infield Fly is allowed to fall untouched to the ground, and bounces foul before passing first or third base, it is a foul ball. If a declared Infield Fly falls untouched to the ground outside the baseline, and bounces fair before passing first or third base, it is an Infield Fly.

Rule 2.00 (Infield Fly) Comment: On the infield fly rule the umpire is to rule whether the ball could ordinarily have been handled by an infielder—not by some arbitrary limitation such as the grass, or the base lines. The umpire must rule also that a ball is an infield fly, even if handled by an outfielder, if,
in the umpire’s judgment, the ball could have been as easily handled by an infielder. The infield fly is in no sense to be considered an appeal play. The umpire’s judgment must govern, and the decision should be made immediately.

When an infield fly rule is called, runners may advance at their own risk. If on an infield fly rule, the infielder intentionally drops a fair ball, the ball remains in play despite the provisions of Rule 6.05(l).
The infield fly rule takes precedence.

No casebook needed. Basically, except for the fact that the batter is out regardless of whether or not the ball is caught, it is the same as any fly ball. So the runners can leave when they would on any fly ball.

They do not need to tag up unless the ball is caught. (But why would they advance?)

Rita

I saw this situation 10 years ago in a state championship game in legion baseball and the communication between the umpires was HORIBLE. The batter popped up just off the infield grass and the infield fly was called so the batter out. Ball was not caught so the runners advanced and the ball was thrown to 2nd base. No tag was applied and the 2nd base ump(4 umpire system) called the runner out on the force play. Said runner gets up and is going back to the dugout thinking he is 2nd out when he is tagged and called out by the 3rd base umpire for the 3rd out and the game ends as it os nit eh bottom of the 11th inning and the team at bat was down 1 run. Because the umpires failed to communicate properly said team lost A CHANCE to tie the game with the next batter. Resulted in one of the longes and loudest rubahrbs I have ever heard at a baseball game. Losing team basically accused the umps of incompetence in failing to communicate and as a result we are being penalized because YOU(The umpires) screwed up. I was broadcasting this game and took me until the drive home to figure out the very very basics of what happened.