As far as publishing AP information on blackjack variants, I saw first-hand how damaging a book can be to a game. I expect I was one of less than a half-dozen people to be playing SP21 before Katarina's book was published. I found some very limited information online, ran many of my own numbers, and shared information with the one other person I knew at the time who was also playing the game successfully. At the time, the game could be played aggressively with no heat. Within a year of the book getting published, the heat started getting turned up on the game, and today, there is little to no distinction in heat levels between SP21 and blackjack. When the book came out, I was glad to have the means to validate some of my own research and numbers on the game. However, the benefit of checking numbers did not compensate for the negative impacts of having the information available to everyone. Even though few people have bought the book and even fewer have successfully played the game in the casino, the mere existence of the book was enough to create paranoia in the casino industry and ruin an opportunity for the select few who put in the hours to do their own analysis.