[nickrego]

As you watch more games, and different umpires, you will see particular characteristics to their stance, that make it personal for them.

Everyone starts out (hopefully) with one of the 'textbook' stances, and then develops that into what feels most comfortable to them. I don't know of any advantage having your arm(s) out gives you, but many umpires do it.

I personally use the Gerry Davis system, by the book. I have always liked to keep my appendages close to me, so they don’t get tangled up in anybody, and to reduce the changes of getting hit. I do High School ball, and having an arm out in front actually blocks the ball from hitting my chest protector, which gets hit a lot. In the Pro’s, very little gets through, and you can do things that wouldn’t be quite as safe in the lower levels. But there is a lot to be learned by watching the Pro’s. Just remember, their world is usually much smaller than ours, and their mechanics reflect that. How fun it would be to always work 4 man mechanics.