To do this properly, you need to do one of two things, and neither is to ignore the cards on the table: 1) Do as Cac mentions above, and use C-D insurance indices, which are somewhat tedious to memorize. MathProf (Michael Canjar) wrote the definitive article on the subject, which appeared in Optimal Play, edited by Stewart Ethier and William Eadington; 2) Keep a side count of aces for insurance purposes, which temporarily adjusts your RC (or TC, for Hi-Lo) to account for an imbalance of aces at the moment you make your insurance decision. I did this extensively, for many years, when playing 2D in Las Vegas.
But, to reiterate, under no circumstances would you simply DISREGARD the cards that you can see before making the insurance decision. That makes absolutely no sense whatsoever.
Don
by: Don Schlesinger
Don, the last thing in the world that I want to do is start an argument and or disagree with you without basis. In my example, I am not disregarding the aces at all, I am temporarily counting them as zero, there is a big difference between those two things. HiLo and KO properly count the ace as negative one overall, the same as the tens. That doesn’t mean it can’t or shouldn’t be counted as zero temporarily when mathematically warranted for the insurance decision, and in this case I believe it absolutely is. Please think about it further and if I’m still an idiot, you can call me that. I agree that side counts would take it a far step further, but this is a simplified version of exactly that, easily implemented, that I believe gives you a mathematically sound result, in keeping with the simplicity of level one counts. I am not far out in the distant clouds like aceside here, and I also never stated that KO was better than HiLo, per his/her statement. I stated that he/she needed to true count if using HiLo.