So, with the switch launch, superdata did this news for the future of NS :

https://www.superdataresearch.com/nintendo-switch-the-superdata-take/

And as you can see near the end, we see the numbers here.

Ps4 numbers seems good for Vgchartz, but Xone are a little overestimated ? Superdata is a serious site or not ?

Doubt it too be honest. The XB1 would be doing around 7.5 million per year if that were the case, which I seriously doubt is true. The XB1 sold roughly 5 million units in the US ALONE last year (and since we do sometimes receive NPD numbers, these should be far more accurate). I doubt when you combine all of Europe (including the UK, which sold roughly 1 million XB1 units last year), all of Australia, South America, Mexico, the ME, and East Asia (most are small regions, but add up), you would only have around 2 million minus the US, and 1 million minus the UK as well. The XB1 does sell poorer outside America and the UK, but not THAT low. I would be more inclined to believe vgchartz estimate in this case, and even then 8.5 million annually doesn't really seem that liberal of a estimate, is it?

Edit: Is this data for the beginning of the year, or now? Because either way, I only counted up till January.

That's for january though, numbers were higher even considering that I guess

Xbox One might be abit overtracked...

But the XB1 figure's are estimates...

english isnt my first language... what I meant is the numbers on VGC for Xbox One might be abit too high then.

it's just an estimate, exactly like our numbers.
For example the link you posted is from January. That means it's probably showing data from the end of 2016.
But we already know that PS4 sold 53.4m at that time.
https://pctechmag.com/2017/01/sony-at-ces-2017-53-4-million-ps4-consoles-uncharted-4-has-8-7-million-total-copies-sold-globally/

Maybe xbox one will have a fight on it's hands for weekly numbers with Nintendo Switch after launch. I can't see the Switch getting close to the PS4 but maybe second place is up for grabs. I suspect the Xbox one will still beat it until a price drop at least though but you never know. Switch might just have some momentum.

VGchartz figures are estimates though based on incomplete data I believe, they are expected to be in the ballpark area but not totally accurate. It's in Microsoft's interests to maximise the number as much as possible, include stock still in retail and include replacement units for hardware faults etc. Enough to tweak the figures slightly upwards.

Its going to be an interesting fight between the switch and xbox, xbox is at an all-time low the beginning of this year, no real exclsuvies and an already announced Scorpio upgrade a few months away.

I am sure both the Switch and the Xbox will struggle this year and pick up in sales next year, it should be close and the Xbox will obv. win in NA and UK but in Japan and the majority of Europe the Switch should win.

PS4 is out of reach in total sales for both consoles, but lets see switch will need a price drop and more third party- and first party games first. But I expect 2018 will be a great year for the Switch and Xbox

For Switch undoubtably..... By then Mario Oddessey will be out, and Xenoblade Chronicles 2, Fire Emblem switch, the Shin Megami Tensei game (hopefully) will be released. Dragon Question XI (ps4/switch) will be out too.

Im not sure why 2018 would be great for the xbox one though. Scorpio is going to be another PS4pro in terms of sales, and Im not even sure what software Xbox one has for 2018 thats exclusive.