index plays?

BMDD

Well-Known Member
#1
Hello. I have been lurking around here for a while and I figured it was time to join and start asking a few questions. I have been playing BJ for about a year and recently took an interest in counting.

I typically play DD, H17, double on any two, no DAS, about 60% pen. My basic strategy is nearly flawless, and I have no problem keeping count. Generally I spread 1:6 using basic high-low.

My current inquiry is about index plays(or indices?). I often see people talk about particular index plays, but i can't seem to find a good list of them. I figured someone on here could point me in the right direction.
 

Wookets

Well-Known Member
#2
Taken from Ken Smith's post in the FAQ Thread at http://www.blackjackinfo.com/bb/showthread.php?t=9666:

Q. If I am counting cards, should I sometimes deviate from basic strategy because of the composition of the remaining deck?
A. Yes, if you know what you are doing...
Basic strategy is the best way to play a particular hand off the top of a freshly shuffled deck or shoe. If you are counting cards, you can detect situations where changes to basic strategy are appropriate. An example might help illustrate this:

Assume you are dealt 12 against a dealer 2. Basic strategy says to hit this hand. However, if you know the remaining deck is packed with tens, sometimes you are better off standing. If you are using the common Hi-Lo count, you should stand with 12v2 if the true count is +4 or higher. If the true count is +3 or less, you should stick with basic strategy and hit.

The "+4" number here is called an index number, and these index numbers can be derived for each decision. They are specific to a particular counting system of course, and can also vary depending on the rules of the game.

Q. Which index numbers are most important, and what are they?
A. Blackjack luminary Don Schlesinger published an article in Blackjack Forum long ago, where he pointed out that a relative handful of index numbers can deliver most of the possible gain from strategy deviation for a card counter. He dubbed these most important decisions the "Illustrious 18".

If you using the popular Hi-Lo counting system, here are the index numbers for the Illustrious 18. These numbers refer to True Count.

Insurance: Insure at +3 or higher.

Stand/Hit:
12 vs 2: Stand at +3 or higher, otherwise hit.
12 vs 3: Stand at +2 or higher, otherwise hit.
12 v 4: Stand at 0 or higher, otherwise hit.
12 v 5: Stand at -2 or higher, otherwise hit.
12 v 6: Stand at -1 or higher, otherwise hit.
13 v 2: Stand at -1 or higher, otherwise hit.
13 v 3: Stand at -2 or higher, otherwise hit.
15 vs T: Stand at +4 or higher, otherwise hit.
16 v 9: Stand at +5 or higher, otherwise hit.
16 vs T: Stand at 0 or higher, otherwise hit.

Double/Hit:
9 vs 2: Double at +1 or higher, otherwise hit.
9 v 7: Double at +3 or higher, otherwise hit.
10 vs T: Double at +4 or higher, otherwise hit.
10 vs A: Double at +4 or higher, otherwise hit.
11 vs A: Double at +1 or higher, otherwise hit.

Split/Stand:
TT vs 5: Split at +5 or higher, otherwise stand.
TT vs 6: Split at +4 or higher, otherwise stand.

Note that the ten split indexes are often ignored, because they are considered to draw too much attention from the pit personnel.

Schlesinger's book Blackjack Attack covers this topic and many more in detail. It's must-reading for a serious player.
 
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