[DownTownTonyBrown]

I feel the low pitch is the toughest part of the zone to call.

I don't know that I'm different from the other posters but I tend to find the limits of the zone AFTER the pitch. I do lend some credence to where the catcher makes his catch but we all know that pitches break and often the catch of a pitched strike can be made a foot below and a foot outside.

I definitely take stock of batter's stature/size before the pitch but by AFTER, I mean that I see the pitch come over the plate and then I find his knees. I set up at the top of the zone (of course that is different for every batter) but for pitches at the bottom and the outside I tend to make my judgement of those pitches by seeing the pitch come over the plate and then looking at the knees or at the outside edge and finally making a yes (strike) or no (ball) judgement. By the use of the words yes or no I'm also saying that I am looking for strikes. I want the pitch to be a strike. The pitcher and the catcher have got to prove to me that it wasn't a strike because I want to make a strike call and I want to keep the game moving.

Concentration is the key. You've got to make those judgements for every pitch, everytime. As soon as you get tunnel vision and call the pitch without thinking about its location, there will be a pitch of questionable location and you will likely miss it.