Pay attention
I am a recreational 21 player who is making the move to more serious play. I have read over 15 books about counting and alternative strategies. I've tried a few of the more controversial methods and counts and had overall success with most. Please pay close attention to the Money Management section of the book. The system works well BUT NOT IF YOU DON"T HAVE THE MONEY TO RIDE THE UPS AND DOWNS. This is a fun, low-stress strategy that can pay dividends if you stick to the math not the emotions. Also try Mannarino's Gregorian Strategy for an eye-opening experience.