Albalaha has an interesting post on his website where he defines breakeven point and how to handle variance.
http://albalaha.lefora.com/topic/4332355/How-to-fight-with-the-worst-enemy-of-gamblingVariance#.Ve7GRfk5G1s
http://albalaha.lefora.com/topic/4332355/How-to-fight-with-the-worst-enemy-of-gamblingVariance#.Ve7GRfk5G1s