User blog comment:Nanamin/Fleet Formation Affects Evasion - Taken from a Japanese Blog Post/@comment-25534439-20150717154141

It's always nice to see more data behind the numbers, but I'll caution that accuracy data is notoriously difficult to formulate due to the amount of unknowns in the systems. Looking at the data here, it seems like each possible combination of Allied/Enemy formations results in different set of bonuses:

The first chart shows a wide difference between enemy line ahead and enemy double line against allied line ahead, while there is little to no difference between enemy line ahead and enemy double line against allied line abreast. As mentioned in the impressions, there is a dramatic improvement for allied line abreast when used against enemy double line, but it isn't really dramatic against enemy line ahead.

Formations may have far more interesting effects than we've been assuming. Very much looking forward to more info.