Indexes are used to make better playing decisions based on the count. This chart displays the data used to generate the 16 vs. ten index and is typical of index charts. The red line shows your advantage by true count if you stand and the green line is the advantage by count if you hit.
Your advantage is terrible either way and gets worse the higher the count with either option. The higher the count, the higher the proportion of tens that are left. The more tens, the more likely that you will bust if you hit and the more likely the dealer will have a 20. So, you are pretty much screwed.
However, we can see that hitting becomes a worse decision more quickly than standing as the count increases. So, we hit on low counts and stand on high counts for the best possible result. The point at which the lines cross is the index, in this case zero.
We will lose the hand more often than not. But a card counter will lose the hand less often than a Basic Strategy player through the use of indexes. We often make a play designed not necessarily to win, but to lose less.
www.qfit.com/book/z511Chart.gif
© 2009 Norman Wattenberger
