the longer you can accurately play. A slight loss in ev for a big addition in the length of time you can put in for a day translates into more earnings. APs that rely on their harvest from casinos to pay the rent and eat have to be opportunistic feeders. To succeed at playing the game for a living you have to play games that offer the best win rates and be well versed in the accompanying strategies. You may have to play a deeply dealt H17 2 deck game in the morning with no DAS and little heat then later that evening play a S17 6 deck game with DAS, late surrender, and an indifferent dealer. This takes a toll on a players stamina. I memorized -3 through +10, DAS, no DAS, late surrender and the plays that give you the lions share of the gain between H17 and S17. After I did that I understood why SW said he used -1 to +6 because he would often have to memorize the numbers for a specific set of rules on his way to the next game. I was planning on playing again because of all the new casinos nearby and I was going to use the I18 as well but after a week long scouting trip the pen was garbage and the games unplayable to me. I played an awful lot of blackjack successfully in my day and the advantage of using the I18 was abundantly clear to me.