Addressing Plural-Account Exploits
Games involving an account with few games on it should have a low impact on rank for accounts with higher game count. Gamerscore can be used as a metric of reputation. Higher gamerscore accounts are more likely to be mains. Matches including second-accounters / smurfs / alts are disadvantageous espionage scenarios for players that stay on their main accounts. The disguised player can learn the main-accounter's weaknesses.