“rigged” is almost a useless term at this point because of how many goofy ways people use it.
50% odds should only generate 50% outcomes if you’ve correctly rated the participants AND nobody deviates. For example, I can’t roll a dice, build a dataset, and then try to predict the results of a different, loaded dice (loaded dice = you’ve improved, started cheating, grouped up, tilt queue, changed mains, got bad chemistry, drunk queue, etc).
That’s what fair 50/50 is. Reflexive to past performance, but not predictive of future performance. Always 1 game behind. Open to past results being invalidated by future performance. Rigged should mean one of those isn’t true.
To “rig” for 50/50, it’s either predict future performance and pre-rig (remove the odds delay), give unfair odds to “force” a macro 50/50 outcome (like 60/40 40/60 60/40 40/60), or rig in realtime by making people lag, miss shots, dc, whatever… could also rig post-facto, boost or dock people’s mmr occasionally
My 2¢:
They pretty much did the second out of naivety (ship matches with unfair odds). Somehow, nobody at Blizzard considered that the new giga buffed tanks might just need to be mirrored to give balanced matches. It’s not predictive, not rigging, but it’s literally a mismade match when the roles aren’t mirrored.
It’s noise. It’s steamrolls, blowouts, low quality garbage. Amplified by loose matchmaking - which btw will still cause the same issue within roles once mirrored, due to bad balancing. (snark isn’t directed at you, but at Blizz)