I only use pairs in two circumstances. One is if I am playing "active" pairs ; that is, if a pair has hit in a particular game twice in the last ten days, I may play it to hit again in the next 5-7 days. In that case, I play the series boxed (ten combos)
The other is if a particular pair is out for over 100 days, I may chase it off and on for awhile. Then I also play the series.
There's simply no way I would play a pair in an "any state" situation. All pairs will hit somewhere because there are so many games out there. Just as every combination will hit somewhere and somewhen in one of the games.
The challenge to Pick 3 is not finding a combination to play; it is finding where and when that combination will hit.
I just don't believe in combinations "for all states". I once did a test for fun...I used the LP RNG to get about 200 quickpicks. Then I boiled them down to the first five of each of the ten sums, and kept track of them for the next three weeks in all the mid day games. I was surprised, but they hit like crazy. Trouble was, you couldn't bet 50 combinations in all 18 mid day games every day and make a profit. (50X0.25 = 12.50 (12.50X18 = $225.00 per day) So you would have "won" a lot....and lost a lot of money.
So whether with pairs or any other system, the only way to go is to play specific game(s) and use a very sharp pencil to keep the number of combos you play down to a minimum, along with a very frugal amount of wagering.