It depends on pricing and such. I can see Scorpio doing very well in the US and the UK if the pricing is right (I'm thinking $399, anything higher would just be MS capitulating market share for good pr, which I just can't see them doing), but they have nowhere near the global presence that Sony and Nintendo have, so I don't think they'll be able to "catch up" in any meaningful way, plus they're going to have trouble continuing to sell the One S if the Scorpio is perceived as too "huge" of an upgrade over it. Sony made the Pro so that the base PS4 would remain a very compelling product, with MS that doesn't seem to be the intention at all. I'm still very bullish on Switch, and can see it selling about 13 or 14 million units by next March, so I think they'll all do well this year. 

PS4 is already too far ahead for the Xbox One to catch it, even if the Scorpio does a better job saleswise than the Pro it won't matter much. Nintendo threw the towel in the home console war when they decided to drop the Wii U, the Switch isn't designed to compete with the other two and shouldn't be compared to them.

Make games not war!

Sorry I just can't contribute anything thoughtful to this topic, because I for instance just don't care about these kind of wars. They are pointless. They are a waste of energy and your everyones time. Just play the games you want to play.

PS4 life time sales = 90 million, Switch = 110 million, XBone = 45 million. Female gamers are the main factor in why I think the Switch will sell the most, they haven't been catered to properly since the days of the Wii/DS, if nintendo can make more lifestyle games like Nintendogs and Brain training, they can match my prediction.

You say female gamers but with the games you've listed, you seem to actually be speaking about casual gamers (granted, many, if not most of these are female). The thing is though: this market is gone. Nintendo's early focus for both the 3DS and Wii U was on this market and it didn't work. Mobile gaming is here now and it isn't going away. Sony and Microsoft's focus on young male 'gamers' has proven to be correct as this market isn't shrinking (I think you've low-balled their sales btw, PS4=120 mil and XB1=60 mil seem more realistic) and so they continue to do well. Switch can succeed, but it won't be because of casuals or females, it'll be because of the appeal of franchises like Pokemon, Mario, Zelda, and Monster Hunter.

This year : PS4 > Switch > Xbone Though I do expect some real fighting for 1st place. Actually I can easily see switch winning but I expect a slow start.
Overall : Switch > PS4 > PS5 > Xbone > Xbox 3

Switch is 9th gen so I do not really see a point in comparing it with 8th generation consoles. I expect the other two systems to release sometime next year. Though I do wonder if Sony and Microsoft will just let the switch dominate an uncontested marketspace for so long.

I disagree, that market is still there, they just have to be catered to. Nintendo focused on core gamers early on, albeit half heartedly. There was little emphasis on original life style games, like Wii fit and brain training. They didn't put as much money into marketing the Wii U as they did the Wii, and the marketing they had was confusing, people thought it was just an add on for the Wii. Mobile gaming doesn't offer casual gamers party experiences like Splatoon, Mario Kart, 1-2 Switch and Smash Bros. 

A console is in competition with every other console which is sold / still gets software. You don't chose your competition by arbitrary terms like "8th gen" or "9th gen" and just ignore the rest of the competition because it is convenient... especially when 9th gen consoles are less powerful than 8th gen consoles.

Why not relive the fun of the last generations version of this thread

I haven't read all teh other posts, I hope we weren't the only two to see this blatant fallacy.