excel.
You already know the basics because you explained them, but just watch each number that hits: how long ago did it hit? From what position did it hit from?
for example, If the first number hit in the last 2-3 games had not hit in 10+ games, it's a fair bet the number hit in the subsequent game will come from WITHIN the last 5-6 games usually, and vice verse': if the first number hit for the last few games is coming from a pool from the last few games, it's a fair bet the next time a game is played the number hit will come from 10+ games old.
Do that for all five positions and you will notice a pattern, although somewhat variable, and it works well for three of the five positions. If it worked on all five, we'd win all the time. That's where LUCK comes in.
I than look at the POSITIONS where a number resides, I pick numbers from certain positions - 1-2-3-4-5 - based on how the last 3-4 games have drawn from.
Again, and I cannot say this enough: a 'system' may be better at helping ELIMINATE numbers moreso than CHOOSING numbers.