The site scoring system is an elo-like system, and is described in some detail here http://www.playdiplomacy.com/forum/viewtopic.php?f=565&t=34913.
This post is to document changes made to the site scoring system in July 2017. The following summarizes the changes made:
- After 4 years experience with the old algorithm, it has now been tweaked to reflect the lessons learnt
- The new algoritm has been reapplied to the historic games to give a consistent position since the rating system started (Feb 2013)
- Player ratings are now available for a number of different categories (ranked games only):
--- Standard (Diplomacy on the classic map with classic rules, full communications and no variants)
--- All-game (all games no matter what the game options)
--- Fog of War
--- Gunboat
--- All games on the Classic map
--- All games on the Milan map
--- All games on the Ancient Med map
--- All games on the 1900 map
--- All games on the Versailles map
More details follow in subsequent posts