Lock:
MK8D
Smash
Odyssey
Breath of The Wild
Sword & Shield
New Horizons
Pokemon Gen 9 (if on Switch)
Very Good Chance:
BotW2: I'm assuming every sequel sells less than its predecessor. If BotW2 is as good as the first, I think it should do it. If it manages to be even slightly better, it will definitely do it. Don't forget about the 1.5-2M people who bought it on Wii U and will likely get the sequel.
Less Likely, But Possible:
Diamond and Pearl Remakes: Let's look back at the DS and 3DS. On the DS, Diamond and Pearl came out first and sold the most. Black and White sold less, and Heart Gold & Soul Silver less than that. Same trend on 3DS. X&Y>Sun & Moon>Omega Ruby & Alpha Sapphire. So from that I expect Gen 9 to sell less than Sword & Shield, and D&P remakes less than that. Therefore I think it's unlikely that they will hit 20M, but I do consider it a possibility given how much Sword & Shield surprised me.
Super Mario Party: I wouldn't have guessed, but with it being at 9.12M already, it could. Seems like the kind of game to have decent legs.
Splatoon 2: I actually would have considered this a greater possibility not long ago, but it seems like sales have slowed down. But with it being half way there, I certainly wouldn't rule it out.
Odyssey 2: I originally had this in the Very Good Chance Category, until I looked up the sales of Galaxy 2; about half the original despite its critical acclaim. So never mind that.
Also, I don't understand why so many people seem to think MK9 will come to the Switch. There's really no reason to think so.
NNID: garretslarrity
Steam: garretslarrity
