You can create a reduction of the integral systems with the guarantee that the combination is present in the number selection then it is also present in one of the produced series.
For example, by selecting 13 numbers in groups of 5 numbers, if you want to guarantee 3 point output, the system will generate 33 series that will contain all possible triads with the 13 numbers.
The ideal reduction would be to never have a combination repeated within the whole system (like the one indicated above) but almost never you can get this result, so the combinations could be repeated within the system. This means that you could put more series into play but with the consequence of multiple winnings.