Capcom's Rey Jimenez, one of the lead guys behind the release of Marvel vs. Capcom 2 was hitting the Unity Boards, to field some questions that had come up from the fans. Why isn't vs. screen character order swapping in Marvel vs. Capcom 2? It was a nice little fake out to bring in someone else based on who your opponent picked first.
Rey: Long story short, switching characters during the vs. screen causes sync bugs. If this was a new game, sure we could probably do it, but with the old base code there were some risks with having it in for online play.
Do the MvC2 leaderboards use Microsoft's truskil rating system? Also, random losses are popping up on my stats, why is this?
Rey: The game doesn't use truskil specifically, but something similar to it. Your overall rating is what determines your rank and that rank is only partially calculated by your win/loss record. Affecting it more are the ratings of the people your playing against. So defeating someone with a higher rating will give you more of a rating boost than defeating someone with a lower rating. With this considered, it is possible to have a lower rating that someone even though they have a better win/loss record because they happen to defeat higher rated opponents.
About losses showing up on your record, for MS games, MS has arbitration servers that determine how to administer wins/losses in the case of an incomplete match (via disconnection or network error) and it will mete out win/losses accordingly. Unfortunately, we do not have control over this system. If it's handing out losses for some reason, we cannot change the arbitration server settings to fix this.