The top two digits in the third position for all 120 box numbers in the Pick 3 game are 8 and 9 (xx8, xx9).
Therefore, when looking at the 20 x4x numbers (digit 4 happens to be the top middle digit in the Pick 3 game), the list can be reduced to just 8 numbers. In other words, when you have not seen an x4x number hit your state for a while (6 or more drawings) there is a good chance that one of these 8 numbers will hit.
The x4x List Reduced to 8 Numbers: 048 049 148 149 248 249 348 349 (8)
Pick3 Master 333 