back count
Back count and come in when the count is good is best. It allows you to only play in positive counts. It is affectionately know as wonging, named after the founder of this site btw. Because many casinos have implemented No Mid Shoe Entry and crowded table conditions in some locations, many players, including myself, have adapted a play off the top and leave or sit out at a predetermined negative count, or wong out approach. This is kind of a compromise between back counting and play all, which still allows you to not play most negative counts.
