Q: Is this for your ebook, or an article? Maybe a sticky for the forum?
Off the top of my head:
-For all types of NLHE, you can't win if you're not aggressive, so I'd say, "not being aggressive enough."
-Tournament NLHE: Chip stacks. It's really important to know how to play your stack in relation to not only the increasing blinds and antes, but also other players stacks.
-Ring Game: Always keeping your stack at max buyin.
What do I know.
