Ignoring anything else -- bugs, bad implementation, etc -- an ideal matchmaking system should be matching people with equal skill, so you would expect to lose 5

Ignoring anything else -- bugs, bad implementation, etc -- an ideal matchmaking system should be matching people with equal skill, so you would expect to lose 50% of the time. That's what is expected in the SC community - someone, Maru or sOs?, said that if they weren't losing regularly they weren't going to be learning anything.