I am going to answer some questions I got in a pm so others can see.. I didn't include the author's name.. so I hope this is ok..
(1) What do you do when there is a zero combo that falls (like 045) and before a double hits, another zero combo falls (like 067) ?
A: What I do here is consider them both.. for ex.. 6, 7, 4, 5 .. since 4 can equal 7.. I would focus on having a double 7 in near future.. another thing.. when 5 is a digit in the warning.. watch out for double 0's.. check your state and see how often that happens.. you will be amazed..
Do you "reset" and look for the double that should be generated from the second combo that fell, or continue looking for the double that should come from the first combo that fell?
A:Both are considered important.. I would watch my p4's if the state has p4's.. if they do not.. watch p4's from neighboring states..
(2) How many days in a row should you pursue the double before giving up and calling it a miss?
A: I continue to play doubles for up to 7 days.. if another double comes that doesn't fit the warning.. beware one will come.
Q: I was back checking a number of games, and often enough for some reason, a zero combo fell and then the game went into a "doubles drout" where no doubles at all fell for a week or more. Somewhere one has to chuck it and say "Back to the drawing board". But how long do you usually keep pursuing it when no doubles at all hit?
A: I haven't seen too much of this.. What state are you referring? Sometimes it will give you fake doubles.. I hate those.. however they can make you some money.. not as much as the doubles..
One may ask: "what are fake doubles".. that is double vtracs.. If you haven't studied vtracs then you probably are not getting many p3 hits..
Here is a site to look over vtracs.. http://www.compulotto.com/concept.htm
how I play the vtracs.. I keep a list of those that fall.. and watch the pattern there..