Why the strike zone is a different shape but not smaller.

From my previous post: Note: The diagram also shows that the top of the strike zone is NOT the "midpoint between the top of the shoulders and the top of the uniform pants". The top horizontal line is clearly lower than the "midpoint", which helps explain the fattened but not smaller strike zone of recent seasons. Rule 2.00 (b): "if any part of the ball passes through any part of the strike zone" See the diagram of the batter's boxes:

http://mlb.mlb.com/mlb/downloads/y2008/official_rules/01_objectives_of_the_game.pdf 

This diagram shows that the two batter's boxes are six inches from the 17 inch wide home base. The ball diameter is about 2.75 inches. If the edge of the ball forms a tangent with the edge of the strike zone then twice the ball diameter must be added to home base width to determine the true width of the strike zone: 17 + 2.75 + 2.75 = 22.5 inches. Note: Also deceptive about the geometry of baseball is that the 60 feet six inches from the pitcher's rubber to home is measured to the back of home base. Most people would judge the distance to the front, which is 60 feet six inches minus 17 inches = 59 feet one inch. I often see pitches called strikes that are tangent with the line of the batter's box, which makes them six inches outside the strike zone. I think this lower wider strike zone of recent seasons is what causes batters to "dive out over the plate". One solution is to bring back the old American League chest protectors for the umpire behind home so that the ump could stay directly behind home. This also provides more protection so that the ump does not need to hide behind the catcher, drifting back and forth at the catcher's whim, and not get a good view of pitches away.