I have heard the suggestion of auto-balancing to even out the playing field, but it does have the disadvantage of punishing people who play well. What the player needs is an incentive to switch to the other team. If the player has the incentive to fight hard battles against high level mechs rather than noobs, they will do it.
What I suggest is this:
Killing a mech on your level: Average experiance gained
Killing a mech higher than your level: More experiance gained
NOV. 27 UPDATE:
I'd be willing to drop the last part because it does punish good players unessessarily, I think now the first two parts I mentioned are enough to prevent noobs from ragequiting. Perhaps average experiance for lower level player kills.
Experiance boost given would be devided into brackets:
1-4
5-10
11-15
15-20 and so on.
The boost I have would be small at best, but just large enough to give players incentive to prioritize fighting and learning from pros.
NOV. 28 UPDATE
Thanks to "ItsThatGuy" for point out to me the mysterious "mech mastery" number. Although I am not sure what all goes into calculating this number, I believe it would be a more accurate representation of player skill than the level of the mech they use. Therefore, I suggest a system that takes into account the opposing player's mech mastery number instead of level.
Edited by Maikeru, November 28 2012 - 12:10 PM.