[quote][b]Posted by:[/b] Jay120171 [quote][b]Posted by:[/b] Domino Theory 2 Sigma is ever decreasing because it can [b]never[/b] increase. [/quote] There are circumstances where your sigma can increase. The system does add some sigma back in prior to each game to keep it form reaching 0 and is also the current mechanism allowing the system to detect a players skill change. Normally it will always be adjusted down but if a player is winning games he is supposed to lose, his uncertainty will not be adjusted down much, then some is added back in prior to the next game thus increasing it.[/quote] In fairness though, with the exception of people that have never lost, it seems that the small sigma increases after the calculation is run through are almost insignificant. I have been thinking though, if they were to bump up that variable a bit, it might appease a lot of the people that are upset with the system. Stale sigma seems to be the root of a lot fo the problems. However, it would probably have the unfortunate effect of dropping Microsoft's new account purchases! [Edited on 06.20.2008 3:07 PM PDT]