You buy into a $1/2 (Limit?) game w/ $100. Your bankroll is usually 3xbuyin, so 3x$100=$300.
Wow. $300 to play $1/2? Amazing.
You say: "It's easy to lose a buyin stack at one sitting."
Look. If you lose $100 playing $1/2 at one sitting, quit poker.
__________________
|