Yeah the leaver penalty sucks, my internet was flaky for a few days so I dropped some games. Took 20 games or so before it lifted
Yeh reading up and it seems that it's a rolling average of the past 20 games. Nobody has worked out exactly what the threshold is just yet though.
I have to say it makes sense, unfortunate for you but your internet problems can ruin the game for others I guess.
Stops most people leaving a game the second a point becomes contested