good numbers, 20 million looks impossible.

Exept for the fact that, for Nintendo, October to january sales equal February to September sales pretty consistently unless we have a non Q3 console launch.

Why not ? If they manage to ship 10+ millions for Q3, shipping another 4-5 millions for Q4 seems reasonable. Especially with a system seller like New Super Mario Bros

I think that's about 300k more than people were expecting

More time and budget too.

its very rare for a console to sell 10 million plus in a quarter and consoles  that have were selling much better then switch on a monthly bases.

Very impressive numbers in any case, going from finances to hardware and software sales.
Switch keeping momentum despite didn't had big games in that time period shows how healthy platform is on market, and this quarter Switch will have easily two its biggest games of year.

Nintendo mentions nine million-sellers this fiscal year, of which six are listed as first-party releases in the supplementary release.

Octopath Traveler is one of them, so what are the other two third-party sellers?

I guess Crash, Sonic Mania Plus or Fifa 19

It seems that Switch did not lose momentum, it's up compared to last year. ;)

I don't think you realise what impossible means, it harder but not impossible.

Switch last year in October-December period sold 7.24m with Mario Odyssey and Xenoblade 2, this year in same time period have Super Mario Party, Pokemon Lets Go and Smash Bros Ultimate, only that is far stronger lineup compared to last year, plus Switch this year has plenty available bundles that didn't had last year. So with that all on mind, Switch could easily this year in same time period sell around 10m. Fact that Nintendo didnt changed 20m forecaste means they counting most for Holiday sales and Pokemon Lets Go and Smash Bros Ultimate.

Even if Switch dont hit 20m, it will be very close to that number in any case, like 17-18m in worst case.