We arent keeping track of the other games, so it is probably just games from 19-34 quickly spike to a top 10 spot then drop out of top 100 and thus sell more or less then PS4. While PS4 and XB1 sales are steady.
If PS4 sells at 80k week 1 then 50k then 40k, while XB1 is at 50k then 40k then 30k for each spot in the weekly. Hypothetically, Then all the games have to do is sell between those numbers and then spike to chart ahead for the week, so 50k-80k is 17-45 in week one, 40k-50k is 30-55, 40k-30k is 27-51.
All made up numbers but if the numbers are close between the hardware but most games sell within that range hourly then spike they can end up ahead.
Yeah, that could be it.
The PS5 Exists.