As of March 31 2017 the PS4 sold 60 million units. At the end of last FY, Sony stated that they expect the PS5 to pass the PS4 alligned sales by the end of March 2017.
So how many consoles would they have to ship in FY 23 if they ship 18 million this FY?
Well 19 million plus 18 million puts them around 37 million. In order to beat PS4 in 2017 they would have to ship 23 to 24 million to achieve that. This is of course possible and and easier to do than 30 million. So we have about 6 million systems to debate over.
I for one believe they could sell them easily. The actual issue is if they can produce enough stock realistically. This is the real debate







