I was watching a table from the beginning of the shoe until about mid-shoe. At about the mid-shoe mark the count was +8, so I jumped in. I won my first two hands but then the count went negative, and stayed negative or 0 for the rest of the shoe. I decided to play out the shoe. Should I have gotten out of there? Do positive counts only last for a few hands per shoe? If so, one must play many shoes to reap the rewards of counting.