Cover Insurance — SCOREs by Penetration

How does cover Insurance affect SCOREs?

Insurance is the most valuable Blackjack index. Unfortunately, betting insurance correctly is also a sign that you are a card counter. Insurance cover is playing in a less than perfect manner in an attempt to look less obviously like a counter. There are six methods of playing insurance depicted in this chart as follows:

1 – Insure all Blackjacks (most common method)
2 – No insurance (Basic Strategy)
3 – Never insure 3-16, always insure BJ, correct index for 17-21 (medium cover)
4 – Always insure BJ, increase index to +5 for all other hands (light cover)
No Cover – Correct Index (normal counter)
Max – Insurance Side Count (max advantage)

Let's start at the top. The top of the cyan colored area gives us the SCOREs using an insurance side count. This is a side count used specifically for the insurance bet and is as good as you can get without hole-carding. The top of the pink area represents the SCOREs assuming normal use of the insurance index. So, the cyan area is the gain in using a side count. Top of the yellow area is for always insuring BJ and increasing the index to +5 for other hands. This adds some cover and yet costs very little. This method of cover looks like a normal player except when the count is so high you have to insure. The top of the blue area displays results if we never insure hands of 3-16, always insure Blackjacks and use the correct index for 17-21. Top of the green area displays results for no insurance (the Basic Strategy play) and the red area is for insuring all BJs and nothing else (the most common play). The last two methods are extremely close in performance.

What about single-deck?

The single-deck chart as usual indicates a substantially greater effect of using cover insurance. Correct insurance play in single-deck is more important.

Sim details

• Six decks, S17, DAS, Heads-Up, Hi-Lo, truncate, Ill18 indexes, half-deck resolution, penetrations from 26-130 cards cutoff by the card
• Single-deck, H17, Heads-Up, Hi-Lo, truncate, Ill18 indexes, quarter-deck resolution, penetrations from 13-26 cards cutoff by the card
• Three billion rounds each for six decks, two billion for single-deck, all sims use optimal betting, full Kelly