Difference War

From BluWiki

The board must be full, and the size-difference between the largest red group and the smallest red group above a minimum size must be larger than the same difference for blue groups. The player who proposes the pattern must choose the minimum size of the small groups. If there is only one group in a given color, the difference is defined as zero. The picture below shows an example in which size-difference between the largest and smallest red groups is 46-1=45 and size-difference between the largest and smallest blue groups is 30-1=29.