Infield fly even if not called

[shipwreck]

The fast pitch rule book that I use states that it is an infield fly rule even if it isn't called by an umpire. The infield fly rule involves some judgement by the umpires so how in the world can the teams know for sure? An example-- bases loaded and no outs, fly ball that possibly could or wouldn't have to be an infield fly. Runners not hearing anything called decide to take off. Then in actuality it was an infield fly, they are in jeopardy. I believe they need to change the rule to say it NEEDS to be called in order to be enforced. JMHO Dave