The part that impresses me is that it means they are tracking at least 17,000 different elements in the game's save state in order to determine exactly how the end scenes play out. That's a lot of detail to track.
They're not. Well, not necessarily, anyway. 8 binary true or false flags has a total of 256 combinations between them. Raise that number to 14 and you have 16384 combinations. Make it 16 and you have 65k.
Obviously they likely have more variables than that and then quite a few combination of variables that are not valid. But the 17k number is probably reached by multiplying the number of different states each of the key variables can have and then subtracting all the invalid combinations.
Edit: And this is without considering equivalence grouping. For instance, BG2 ToB had a total of ~15 companions of which you could choose 0 to 5. So for slot 2 you have 16 options, for slot 3 you have 15, then 14, then 13, then 12. That's a total of 524k different permutations of end game credits, and that's before we consider romance options. But that math is deceiving because the individual companion epilogue was static and entirely unaffected by who you parties with or what you did. Jan's ending is the same in every single permutation where he appears, so arguably they're all equivalent in the Jan-aspect.
