How many major exclusives does the Switch need to gain out each year to maintain popularity?

[zorg1000]

1 major and 1-2 medium sized 1st party titles each quarter is what they did this year and it would be wise to continue that formula.

Q1-Breath of the Wild, 1-2 Switch
Q2-Mario Kart Deluxe, ARMS
Q3-Splatoon 2, Mario Rabbids, Pokken DX
Q4-FE Warriors, Mario Odyssey, Xenoblade 2

They can have the ocassional quarter without a mega release as long as the gap isnt too large and there are 2-3 medium sized games in between. Heres a sample of what 2018 could look like.

February-Kirby
April-Smash Bros Deluxe
June-Yoshi
August-Fire Emblem
September-Animal Crossing
October-Metroid Prime
November-Pokemon
December-Mario Party