I've been a player for a long long time (12/04/2012). One thing that has constantly been complained about is people in higher tiers not knowing how to play well. We've all seen the players. Driving around in a Tier 9 or 10 vehicle, and they don't seem to even know the game. They constantly move their turret in strange directions, seem almost to be driving drunk. Then afterwards you look at their record and realize they only have like 1k battles. How are they at tier 9 or 10 with 1k battles?! Well, shove enough gold at stuff and you can do it.
So what about this idea. Create milestones that have to be reached to unlock higher tiers. The idea isn't all that unique, other games I've played have done similar things. You can't get past a certain point until you've done x and y.
So here is what I was thinking as a more-or-less kinda milestone map.
Tier 1-5 completely unlocked for all players.
Tier 6 – Locked until you get at least 1k battles and have a WR of at least 45%
Tier 8 – Locked until you get at least 5k battles and have a WR of at least 47%
Tier 9 – Locked until you get at least 6k battles and have a WR of at least 48%
Tier 10 – Locked until you get at least 8k battles and have a WR of at least 49%
To me this does two things. Keeps the new players in the lower tiers until they learn how to play. Also keeps the poor win rate players out of the upper tiers of battle. Of course, actual implementation the numbers could be adjusted. Maybe 49% is too high for Tier 10 because the average WR in the whole game is only 49% so maybe it should be 48%. I don't know. Just threw numbers out there.