So its already halfways to those 20m.

End of year there is a Possibility of 15mil+

Okay, I was being stupid earlier on my first post. Considering that Switch is at 20 million units, and I expect it to do at least 80 million, the fact that Zelda is one of those evergreen titles it only makes sense that new Switch owners will pick up these evergreen titles. 20M is definitely a possibility. 15M at least.

Looking like 15m total by the end of this year now.

This is exactly what I was thinking.  BotW is entering a new category.  It's transcending far beyond what we normally expect for a Zelda game.

Wow, that's wild, it's actually ahead of schedule for his prediction when you include digital. This might actually happen, and is clearly already close. By the end of this year, physical plus digital for both Switch and Wii U versions will almost certainly be 70% of the way there. This means 15 million is almost a certainty, unheard of for a Zelda game's launch versions. Hell, I'd be willing to bet every version of Ocarina combined, 64, 3D, Master Quest, Collector's edition, and all the virtual consoles, would only barely make 20 million, and here Breath of the Wild is on track to pull 15 million from just one launch version, maybe even 18 million. That's mainline Pokemon numbers.

Another interesting thought is that if Zelda is looking like 20 million is possible, then for Mario, 20 million is a certainty, on par with Super Mario World. That's the first time a 3D Mario has pulled 2D Mario numbers.

15m maximum? It shipped 2.6m this year so far (6 months). Would you like to take a bet that it will officially hit 15m by March 31st?

It really is interesting. Btw, a proper fresh 2D Mario on Switch would probably match/surpass the NSMBWii level of sales.

Somehow people forget Zelda Botw is currently performing better than SMO in Japan and US. I take back my prediction earlier with the chance of a new 3d Zelda released in 2019 which is impossible.

Only if they can shake the NSMB brand. It should probably stay 2.5D, but it needs another rebranding the way the original NSMB did. Maybe even a moderate shakeup in the formula. NSMB is just too stale. It was one thing when it flopped on the Wii U, but it had no business doing worse than 3D Land on the 2DS. Something is definitely wrong. The series needs some kind of shakeup. And hey, a new style like that will give Nintendo another Mario era mode to put into the next Mario Maker, which would be fun. I've a feeling the next Mario Maker will be an explosive jump in sales from the first as well.

Yeah, that's what I mean. I agree, they need to shake up the series à la Odyssey (3D Mario got stale too with 3D World, but Odyssey changed that introducing new mechanics and visuals). If they just port NSMBU or make a generic new one, it would probably end up doing about the same as NSMB2 on 3DS.