Question. Taking insurance when index not completely reached/exceeded yet.

I was playing Double Deck the other day and had two betting units out. Dealer showing and Ace and I held Ace, 8. Therefore count went lower I figured. Could not see the one other player's two cards at my table. I decide not to take insurance. I hit and receive a 3 for 21. The other player hits and gets a 4 and stands. So naturally after those two low hit-cards out, dealer draws a ten for Blackjack. Would you automatically take full insurance when you have more than one unit out or would you take partial insurance or none in that situation? I'd like your opinions. Thanks!

Is this a NHC game?

BTW, the value of the cards seen doesn't matter, only matters if they are tens or not.


100% insurance correlation would be:

10's: -2
non-10's: +1
start at RC = -4*decks
insurance is an even bet (no edge) at RC = 0. House has edge with RC < 0. Player has edge with RC > 0.


In the situation you described, there's A, A, 8, 3, ?, ?, 4. The two ?'s are unknown cards (what the other player had).

That gives us:

-8 + 5 = -3 RC.

Even if both of the other player's cards were non-10's, the RC would go to -1. Still a negative proposition bet.

If you're not using a perfect insurance correlation count, then you simply do or don't take insurance at the triggered index. For hi/low the index is TC +3. If it is TC +2.5, you do not take insurance. If it's TC +3 exactly, you take insurance. It's 100% math, you simply do not take insurance no matter what unless the TC >= +3.

Is this true for all decision rules in I18 and F4? Take the floor rather than rounding it? Because the Wizard suggests rounding on his site.

Getting really nit-picky here, but I believe it depends on how the indices were generated. If they were generated by flooring, then you floor. If they were generated by rounding, you round. As far as I know (I may be wrong), HiLo indices were generated via flooring. I think most count systems use flooring, but I think some systems' indices were generated by rounding.

The more precise your system is and the more precise you estimate decks (full deck, half deck, quarter deck), the more of an impact it'll have on your game. [Meaning if you use the wrong method in a very precise system you'll have more of an impact than using the wrong system in a not-so-precise system.]


But in reality, it has such a little impact on your game, I say do whichever is easier. IMO, flooring is easier.

Quote: ArtooDetoo

Is this true for all decision rules in I18 and F4? Take the floor rather than rounding it? Because the Wizard suggests rounding on his site.

This is a bit more of a personal decision, in my opinion. I round when it's very, very close (sometimes) and floor at other times. For the most part I use the exact indexes, so I don't round (most of the time).