General 

1. Green to Represent Passage
2. Bottom of Strike Zone
3. Makes the Hitter Protect and Expand
4. 2 Shorter Because Middle Easily Recognizable

Purpose

1. Identify Quality Strikes
2. Get Ahead of the Hitter
3. Reduce Pitch Count
4. Keep Fielders and Umpire in Rhythm

Sequence

1. Most Important Zone to Command
2. Always Quality Spots Even or Behind in Count
3. Allows Other Zones to be Utilized
4. Use 2 Zone with Off Speed Behind in Count

Selection

1. Use all Pitches in Go Zone
2. Command Off Speed Pitches in Go Zone to Disrupt Timing
3. Further Behind in the Count, Target More Towards Bottom Edge of 2 and 4 
4. Further Ahead in the Count, Target More Towards Edges of 1 and 3