Another suggestion: disable all variant maps :)
It would be an improvement if only the classic standard Diplomacy map would be playable here.
If you like variants, you could go to vdiplomacy.net, or one of the other sites.
There exist thousands of variants; it's always quite arbitrary to decide which to include and which to exclude; the criterion on vDip seems to be that a variant is properly coded. I don't know what the requirements here on webDip are, but I guess it's highly unlikely any new variants will be included. Why is Milan disabled? Why is "Fall of the American Empire IV" available, but "Abstraction" not?
If you want to allow playing variants here, then why not truely balanced variants, e.g.:
http://vdiplomacy.net/variants.php?variantID=11
http://vdiplomacy.net/variants.php?variantID=21
http://vdiplomacy.net/variants.php?variantID=93
Besides, points, rankings, and scoring systems tend to be more effective if they compare relatively equal things, e.g. achievements on the classic standard map.
Solo-victories etc. tend to be easier to achieve in some variants than in others. Including statistics from different variants into a single ranking makes me feel somewhat uncomfortable.
Either disable all variants, or completely exclude them from the rankings, or alternatively, have different scoring systems and rankings, one for each available variant.