To be honest, 50- 50 algorithm is good, but winning/losing streak is too long. If it was like:
2-3 wins
2-3 losses
2-3 wins
2-3 losses etc.
it would be quite fun and balance. But instead you win like 6-7 matches and then basically you can throw other 6-7 matches because you know you will face harder opponentes and most likely lose. And when you loose +5 matches in a row you lose motivation to play this game.