Definitive possible, PS3 have sold 1/2 of PS2 sales, i predict PS4 at 90m lifetime, so, PS5 can have a 50% dropped like is happen with PS3 and sell around 45m.

Unluky, but can happen. Also, why you think 45m is the maximum of what XBOX can sell in the US?

It can even sell 60m for what i think. SUPER unlucky, i know, but can happen.

the ps2 was an anomaly same as Wii.  ps1 sold 100m.  ps4 is also bound to sell 100m.  ps3 is the only one that sold below expectations but if you look carefully for all the obstacles that ps3 went through such as price launch($600), 1 year later than xbox(europe was 1 year and a half later), arrogance from the CEO, no games and still manage to sell over 80m, you can tell that it's almost impossible for a ps console to sell 45m.  heck the avarage for all ps consoles will be over 100m  when everything is said and done with the ps4.  I don't know why you see ps4 at 90m when ps3 isn't too far to that number and ps4 almost have europe and japan market for its own compare to xbox.  Also add that ps4 won't have the same fierce competition that ps3 had last gen.

of course anything is possible, will never win a generation is also a possible... 

Of Course they can, Xbox is a brand just like Nintendo and Sony and Sega etc. There are no advantages that favour any of them, if anything Xbox has a huge advantage since they are under one of the most wealthiest corporations in the world.

If Xbox really wanted to win the console market they would just sell X1s for $50 world wide, they can afford to do that (they wont because that wont look good on the shareholders) but if they really wanted to they can. This is why gamers need to stop looking at Sales charts. Consoles can sell more based off many things and quality of the product isn't included. They can sell by Bundles, Price Cuts, manufacturing issues, Blu Ray Drives, and simple advertisements.

It makes me laugh when a gamer comes to me talking about "This console is the best because of its sales" when I look at them thinking, there's another suckered in by the marketing. No one seems to care that the Wii dominated the competition last generation because of my points above, Cheaper, bundles, advertisings can lead to winning a console war not games. Lucky for Nintendo's Wii they covered all bases including games.

Lets be honest here when we look at the PS4 and XB1

Ryse - The Order
DriveClub - Forza Horizon 2
Killzone SF - Halo MCC
Bloodbourn - Dead Rising 3
Infamous - Sunset Overdrive
Knack - Ori and the Blind Forest
TLOU-RM - State of Decay-RM
Little Big Planet - Project Spark
Street Fighter V - Killer Instinct
Uncharted 4 - Rise of the Tomb Raider
God of War 4 - Gears of War 4

and many more to come etc.

I haven't put them in the best order but that's only but lets take a good look at that list and can you see a clear winner? Both have better games then the other, Where PS4 has the better Horror game, XB1 has the better Racing game etc

There isn't that much of a difference in terms of quality between the two to justify a superior console and to say one is selling better then the other based off its own library of games. There both equal when it comes to the games, I tip my hat off at Sony for there great marketing because honestly that's all it takes these days to sell consoles. With the change of CEOs at Xbox, they will learn from this and only become better for it with there next effort.

PS3 had a slow start last gen and even out at the end of the generation, XB1 is having a slow start this generation and will most likely end on the same note as PS4.

Gamers need to rejoice and stop hating on other systems. I am a PC gamer and to see people talk down at one another is just sad and gives gaming a bad name. If the 360 didnt do what it did to the PS3 last gen, do you think the PS4 would be what it is today? No.

This is my honesty PS4 prediction (LT):

2015: 15,000,000 (33.5m)
2016: 17,000,000 (50.5m) peak year
2017: 14,000,000 (64.5m)
2018: 11,000,000 (75.5m)
2019: 7,000,000 (81.5m) PS5 RELEASED ON NOVEMBER 2019
Other sales after 2020 for break  ~90m sold.

Of course is my prediction, PS4 can even sell +120m lifetime, why not. +100m is not crazy, but can i know what is your year on year prediction?

For the PS5 at 45m... yes, unlucky, but who know, we know NOTHING as for now... maybe can seriusly become a new PS3... any way, even if for now is impossible predict, i think PS5 will sell ~70m.

Can sell between 40m and 200m... just what i think.