Why 50% win rate is stable at every rank
Ranked ladders in competitive games maintain a 50% average win rate at every skill tier through matchmaking. If players in Diamond rank average 45% win rate, the system promotes some of them out of Diamond, leaving those behind with higher win rates. If they drop to 55% win rate, the system demotes players back in, rebalancing. The system treats each rank as an equilibrium: if a rank gets too strong, the MMR system pushes players out; if too weak, players sink in from above until the win rate restabilizes to 50%.
Climbing ranks through positive win rate deltas
A player climbs not by having a high absolute win rate, but by having a win rate above 50% in their current rank. Someone with a 52% win rate in Gold will steadily climb. Someone with a 48% win rate will drop. The fact that Gold players maintain a 50% average does not mean they are stuck; it means the population of Gold players always has those at 48% (declining), those at 52% (climbing), and the median at 50%. A climber with 56% win rate will rise to Platinum, where the same dynamic plays out.