Tobold's been talking about having a 50/50 win/lose ratio in world of tanks, derived from the skill matching system.
He says it means your choices really matter on the field.
But think about it - overall, he's at fifty fifty.
You could flip a coin and get the same set of results!
Indeed a perfectly balanced skill ranking system just makes your skill absolutely moot! Flip a coin - same result in the end!!
However, I don't know if world of tanks has skill tiers like quake live does. Quake live has four tiers, so basically you can move up them if you do happen to make the right moves towards winning consistantly. So in those terms I'd pay that your choices matter.
But by itself - a perfect 50/50 is, just by itself, a complete waste of time in terms of gaming. It's just a hamster wheel.