This just doesn’t make any sense to me and here’s why.
Obviously it’s not my fault(or anyone else’s on my team) that we lose with one player down and fact is you do lose 5v6 almost for sure. I mean, even the claim that matches are balanced and there is 50% chance for each team to win supports that, and if that is the case then you lose no matter what. And the question is why do I get punished for the outcome of a game that I’m no longer in control of. Why do I lose my SR? If games can be cancelled if player leaves early in the match, so then why not implement something similar for the entire match, wouldn’t that be more fair to me and others in the same situation. I mean, leavers happen way too often and that just staggers progress which makes me (and I bet not only me) not wanna play the game at all
Because it can be 2 rounds in, your team is 90% almost about to win it, and the enemy leaves only to cancel all that hard work. But they could work around this. Maybe before the 4 minute mark of the game, the game is cancelled.
The simplest answer is that it should never be preferable to have someone leave a match vs finish the match.
Anything that makes it possible to save SR by having a leaver is about the most easily weaponized concept in any competitive game, nevermind this community.
Or you can just get no or significantly lesser penalties in such situations
The real way to average out the outliers like this one, is to play a lot more games. But it is not available for everyone to play a lot of games, so the problem would be amplified for those who can’t.
See my previous post
Easy fix
I think the team with the leaver should lose no SR but the enemy team IF they win should still get the full 25sr. If the team with a leaver wins they should get the normal 25sr too. No point in punishing people for something they have no control over 
This makes it preferable to have a leaver on your team when you are losing.
Any system that exists in that format will never get added to the game, i’m sorry.
If you aren’t able to answer “how would the community weaponize this idea” in a positive way, it’s a bad idea.
Who will actually go through the effort to get a friend to go on an alt and leave to not lose sr. At a certain point the time you cant play ranked just becomes too long for it to be an effective strategy. The idea overall is good and shouldn’t be dismissed because of a few rotten apples 
Plenty of people would (and already) do this, your idea would simply give them a much larger incentive (especially on console where alt accounts are unlimited and free)
You want your idea to be a good one, and in fact it comes from a perspective of wanting to do good for the community, and that’s admirable.
Unfortunately the number of rotten apples is anything but “few”
This doesn’t even account for the incentivized harassment of underperforming players.
This community doesn’t need another weapon to use on each other. Not something you can just dismiss because you want your idea to have merit.
On top of what they have been said, what about the team without the leaver but anyway was about to win the game? They lose all the effort they put in just because someone on the other team leave? What if it’s intentional?
Wait what?¿?¿?¿?¿?¿?
Team 1 vs Team 2. Team 2 is just about to win. Team 1 member decide to rage quit before the game ended. What will be with Team 2 who were the better team? Why would they win less SR for that(or other compromising solution)?
Another option, though not one I think would be very good is to mirror match, if team 1 has a leaver, the sistem pauses the game for 30 seconds, and asks the team to give a player up from the same role. The second leaver wouldnt get any penalty and would win the SR the team won regardless if its his original team or not for being a good samaritan.
It could be abused, buuuuut im not sure it would be worth it
Cheers.
I guess you are right but I can’t really see it all that easily abused considering current policies for leaving penalties (like you get banned from current season if you leave 5 times or something)
How do other games deal with it?
I know you get bots for leavers in cs:go, players can even control them after dying I guess
That whole smurfing problem people always complain about? Thats people on alt accounts they can use to circumvent stacking too many leaves on one account.
And alt accounts are not only unlimited, but free on console.
Because otherwise it’s primed for abuse.
“We’re losing. Mercy, you’re three different slurs, and should uninstall yourself from life. Everyone, tell Mercy how much she sucks so she gets upset and leaves.”
there we go, my SR is safe.
Because it could be abused if no one else got punished, you could have a dummy account to cancel matches not in your favour.
Best solution is to take the SR loss as normal but the person who leaves/disconnects should take a double SR loss.
Yes I know it’s conteoversial to say that a disconnect should be punished but that persons poor internet connection just ruined the game for their whole team .