Bungie has detached Halo 3's ranking from the Trueskill system that drives matchmaking. Previously, the on-screen ranking users saw reflected how players would be matched up competitively, meaning someone with a high ranking would most likely be a competent Halo 3 player. That's not necessarily true in Halo: Reach. To be clear, Trueskill is still driving matchmaking, but Player Investment is more reflective of the amount of time someone's dedicated to Halo: Reach and not necessarily their skillset. Someone can have a high Player Investment ranking and be a terrible player. But since Trueskill is tracking that data in the background, away from users, it will still match players appropriately. So, don't worry: terrible Halo: Reach players will be matched with other equally-awful Halo: Reach players.
You can read the full interview .
[g4tv.com]