Why unlikely? It’s pretty simple to be honest.
People’s skills don’t grow overnight. It takes time, lot of time to improve.
When the skills exponentially grow overnight, it very often means they sold their account or something else (cheats, boost). It wouldn’t be too strange if a Company would automatically open an investigation ticket on the player. (some famous ones actually do that)
I never said there’s a 50% forced lost, at least not in competitive.
I think on OW it’s more reasonable to have 15% forced lost no matter how good you are, and a 35% of negative trend to win.
Reached this point, you simply need to assign a hidden carry-factor score to each player, and calculate which queue they should be assigned based on their win-rate: forced lost, negative trend, positive trend, forced win.
The aim is to make climb possible, but at the cost of burning time.
If your question is how to calculate the hidden score for each player, there’s plenty of data you can use per match.
I’d probably calculate the average per minute, and flag whoever had a low performance on consecutive matches for their specific rank.
Those flagged ones will then be used to drag down the ones who have carry-factor by causing a forced lost.
In fact, in your correct rank you get 50% of win-rate, because you will win all the favorable ones, and lose all the other ones.
If a player is able to outsmart the algorithm by winning an otherwise forced lost match, it’s not a big issue. You can just force him another forced lost match.
People may leave/disconnect, hard/soft throw, pick bad heroes, abuse meta, etc, so it’s not impossible.
OW queues take several minutes to be proceeded, which means many factors are calculated. (I think they also consider which maps and heroes they previously played)
Otherwise, the queue time would have been instant for tank and support players (and not 3+ minutes).