Common Colour Balance with US sheets

WoTC could have maximised variance and colour balance, achieving 98.7% packs with all five common colours, and only 1.3% of packs with four common colours, by using their existing US print runs with the structures I proposed for mirage. At a slight hit to variance, 100% packs with all five common colours could have been achieved with the US print runs and the following structures.

A	A	A	A	A	B	B	C	C	D	D	50% of packs
A	B	B	B	B	C	C	C	C	C	D
A	B	B	B	B	C	D	D	D	D	D

Alert - this is not how the real packets are, just what I thought they should have done.