So I evolved that "Trajectory matching" utility PantherLotus inspired recently. Matching sales at one point can be useful in narrowing things down, but I thought being able to be more specific would be even better. By matching games at multiple points, you could try to find ones with similar legs. While I succeeded in making this work, the initial example I made for testing ends up showing games with some wildly different outcomes, so it goes to show that just because there are similarities, it doesn't mean there will continue to be.
Games that sold between 95K and 105K in 3 days - 30 matches
aaaand between 135K and 145K in 10 days - 4 matches
aaaand between 225K and 235K in 52 days - 2 matches
Even after matching that far, though, the games then diverged. One is last seen at 252K, the other at 373K.
That would still be relatively leggy for a game that had such a drop into week 2 and week 3.
Actually, it was using the first version of this tool for Shiren last night that made me realize multiple points could be useful. So many matched the "after 3 days" or "after 10 days" number that it was hard to narrow down the ones which had a decent opening but then poorer legs. So now I'll try plugging in numbers to see which ones are near-matches after 1 week
and 3 weeks.
Between 53.5K and 63.5K after week one, between 73K and 83K after week 3.
13 games matched. Of those, only 2 passed 100K; at least while on the charts that are currently in the database.
Making things match a bit tighter, so
in both cases they must match within 3K rather than 5K, there are only 3 results. One game eventually reached 92K, one game eventually reached 108K, and the other is Disgaea 3 so it's too recent to know how things play out in the long term.