Hello, are the majority of all the variations from basic strategy dependent on hi-lo or are they precise for other card counting systems such as hi-opt 2 and red 7? If you know the majority of the variations, hi-lo without problems and basic strategy without issues, would you recommend to change to a more difficult card counting system or learn to shuffle track for example? If you recommend shuffle tracking, could you please suggest me a good website with much information about it, because I have lack of information about it.