Since I started playing everybody who joins my table(instead of bumhunting like last months or since learning HU) I got some problems with "selection". Now I get kind of really different players and also a lot of better players. But now my problem is how can I get some fast information that I have a real edge on my Villian? Or at least knowing that he is not running over me. Sometimes I get this kind of strange feeling and I dont know if I dont have a feeling for variance or if Villian is running over me.
Should I have nearly always the feeling that I am controlling the game and my Villian when my goal is grinding money? And sit out all other guys who I dont feel I can run over a solution for selection?
I improved a lot but I am bit afraid that I am leaking money by bad selection. Also those kind of games who lasts longer(300+ Hands) vs same Villian is kind of new to me and are a lot more stressful that playing bum after bum.

When to quit? Any suggestions?