Currently, players are credited for evolving an existing structure in All Hands puzzles if they improve the score of the template structure to the nearest full point. However, this give players an incentive to improve a structure to XXX.000 rather than XXX.8 or XXX.9 if they want to get a top rank, as any fractional score above zero would make it easier for other players to surpass them (especially if it's XXX.8 or XXX.9).

==> A possible way to get around this problem is to require a player to improve an existing structure by a set amount, say 0.5 points or an entire point, to pick up the credit for the evolution.