Switch needs roughly 1.6 million within the next 8(!) month to keep the lead after PS4 holiday 2017.
Seems like in 4 month the gap will be huge. For sure at least 5-6 million, but probably even 6-8 million. When assuming "only" 500k september, 500k october, 1 million november and 2 million december (= 4 million for the rest of the year), then the gap would be 25.4 million vs 19.9 million. Thats a gap of 5.5 million. And I am pretty sure these numbers are on a rather low level. It also could be 6 million for the rest of the year, which made the gap grow to 7.5 million.
This will be very interesting.