[collinb]

I find catchers obstruction a difficult call to sort out.
In the five years I have been umpiring I have never actually seen the catchers mitt obstruct the batters bat. I have learned the best way to determins that it has happened is by sound. The ball tipping the bat makes a tick. The bat hitting the cathers mitt makes a thud. On two different occasions it was questionably whether the sounds were thud tick, or tick thud. A thud tick would be obstruction for sure. A tick thud could possible be the bat hitting the mitt on the back swing. On a third strike if the bat knocks the ball out of the catchers mitt would'nt that be interence on the batter?
Of course the worst scenario is the thud, gasp.
This is the soung of the bat knocking the catchers mitt out of the way from catching the high inside pitch. The gasp is the sound of air leaving your lungs after taking a unobstructed hit to the chest. When that one happens the last thing on your mind is catchers obstruction.