Explanation of Rule 4:
You must Poke at least as many POKES in your current cigarette as you 
POKED in your Last one.
As you read the way PBYS works, you will see that there are three things you are trying to accomplish:

1.  Reduce the amount of Tar/Nicotine/Particulate matter you inhale;       which will wean you from the Addictive portion of your habit.

2.  Establish and increase the "PITA Effect" in your overall smoking        habit which will help extinguish the behavioral portion of your             habit.

3.  Protect yourself against the AVE problem which defeats the                 efforts of most people trying to control their smoking habit.

To do these three things, you must maintain your achieved "poking" level (number of pokes per smoke)at all times.  If you do not, you will be teaching yourself it is OK to cheat, and that will destroy your efforts.