Dave & Jake, your right!
I spent the afternoon at my sons baseball games and thought it out. Even drew it out and realized I only needed the middle patch as well.
Daves calculation was spot on.
Taking this further the measurement between the upper & lower patch could be up to 28' (on my sail) and would require a middle patch.
And if the upper & lower patches were within 14' then, as stated earlier, the center patch isn't necessary.
When making the first measurements I had already built in a cushion by measuring 6'8" instead of 7' figuring for material stretch etc.
Thanks for your help guys!