50/50 matchmaking is fundamentally flawed
Matchmaking should be either random, or pair you with similar skilled players at all times.
The main reason being that pairing you with lower skilled players makes you a WORSE player, as you have to adjust your play style to compensate for bad plays, turtlers, or other strategies you don't see in higher end play.
Even if youre just above-average, playing with bad players will greatly affect your chances of winning. It means that your win/loss has nothing to do with your skill level, but solely on your ability to adjust your play style (without knowing the skill of your players), which is impossible.
A better matchmaking should simply match you randomly against all rank 1200-1299 assuming you are 1239 or 1299 or 1200. throw out the 50/50 algorithm. its makes no sense.