The analysis is supported by the mR chart, which indicates that the Session 7 and Session 8 range result lies just outside the upper range limit.

Other players on the team showed several out-of-limit signals, and analysis showed that the durations of their sessions were abnormal in comparison with a normal one-hour session time.

Try to remember that a session length should be about an hour. In my team-data analysis, I noticed that several players had put in a 10-hour session resulting in a Signal 1 indication of abnormal variation.

Keeping to constant (1-hour) session lengths will help to prevent these type of false signals.

Signal 2: 2 out of 3 consecutive values beyond Sigma 2

Signal 2 is an indication of potential over-betting or some other type of special cause.

One should use a cause-and-effect diagram to analyze the effects in greater detail.

The idea of a cause-and-effect diagram is to start at a high level and then to drill down into more and more detail to determine as many reasons for the abnormal variation as possible.

Signal 3: 3 out of 4 consecutive values closer to one of the limits than to the central line

Signal 3 indicates a slightly more pronounced and lasting problem when compared with Signal 2.

This pattern is often seen in those who over-bet. Again, one should use a cause-and-effect diagram to analyze the effects in greater detail.

Signal 4: 4 out of 5 consecutive values beyond Sigma 1

This signal indicates that it is abnormal for too many data points to be outside the normal plus and minus Sigma 1 range around the average.

I would be really suspicious of a player who showed this type of results pattern. If the results were below the lower sigma 1 level, it would potentially indicate that he was stealing from the team or that he was playing too often against a cheating dealer.

 © 2009 Norman Wattenberger