“It’s a complex problem. We do have the five-minute rule: if you find your connection’s poor you can drop out within the first five minutes. After that there should be a penalty; just in the online world there are complexities that mean by the time the data comes back to our servers, something there means it doesn’t award the win to the right person. So we’re always looking to improve that.” – 2010 FIFA World Cup line producer Simon Humber
This is an easy one just use the Tatsunoko vs Capcom solution. Match up the repeat-disconnecters with other repeat-disconnecters and let them play each other to see who can leave first.
-Justin
