If this system fails, the game becomes a frustrating, unplayable mess that bleeds players instantly.

Many players believe that matchmaking is intentionally rigged against them, constantly forcing them to fight 'hard counters' after a win streak.
Trophy and Rating Systems
Most modern strategy games utilize a modified version of the Elo rating system, originally designed for professional chess.

If the system matches you perfectly, you should mathematically have a 50% chance of winning every single game you play.
It only looks at your numerical rating.If you face a hard counter, it is pure statistical variance.In the lower arenas, the system often includes 'bots'. The Free-to-Play Dilemma
The standard Elo system works perfectly for chess because all pieces are equal, but tower rush games feature upgradeable cards.

To combat this, developers have implemented secondary checks that look at the player's King Tower level.
Matchmaking FactorWeightTrophy CountAbsolute Highest PriorityUpgrade StatusThe system tries to match levels, but will abandon this check if the queue takes longer than 10 seconds True Fairness
By artificially capping all card levels to a specific number, the algorithm can rely purely on the Elo rating.

Trust the math, ignore the conspiracy theories, and focus on improving your own gameplay.