Dear Jeff, why is it that when I rejoin a game after being DC’ed withing the first 10 seconds I still lose SR? It seems reasonable for the game to continue if someone joins within 10 seconds, even 20. And beyond that, losing 50 SR? It seems like too much.
Rejoining a game without penalty is only possible during certain phases of the game and within a timely manner. If you leave a game either during the pre-game or during the first minute of the game, the game will automatically cancel (remember the 10 second rule does not apply to the leaver, but as a warning to other players that the match will cancel). You can rejoin the match during the initial hero selection screen if you are lucky enough to quickly reconnect though.
Otherwise, you can only rejoin any-time after one-minute of match time has passed up until the match completes. However you only have two minutes to do so without penalty. If you rejoin a match after two-minutes, you will still automatically be marked with a loss an be penalized with a -50 SR cut and a ten-minute suspension. This rule ensures that no one can abusive the leaver system by attempting to return to a match after deliberately leaving in order to avoid such penalties. Furthermore leaving three or more times in a single match will result in an automatic penalty. If you fail to return to a match by the time it ends normally (regardless of match result) you will be penalized.
Additional details can be found here: