For example, we may have over-bet, we may have had some sort of dealer tell that we were able to exploit, we may have had dealer help in some way, etc.

There is a reason and we need to investigate further to find this “special cause.”

 On the downside, we should never have a loss exceeding 104.36 units over an 8-shoe trial under the identical conditions that SBA is facing.

If we do, then there is a reason for this also. It may be that we are over-betting. It could even be that we are under betting. It could be that we are being cheated.

And again we would need to investigate further to find the cause.

Let’s add the “Sigma 1” and “Sigma 2” lines to our XmR chart. Sigma 1 on the X-chart is calculated by the formula Sigma 1 = X-avg +/- .89 * mR and Sigma 2 = X-avg +/- 1.78 *mR.

For reasons beyond the scope of this text, we do not add Sigma 1 and Sigma 2 lines to the mR Chart.

Figure 12.5 displays a complete XmR chart.

 © 2009 Norman Wattenberger