We are comparing the consoles to themselves, not each other, so I don't really understand the point of this comment

Just a thought.  I hope next gen will be more interesting and Sony will have stronger competition.  Otherwise it's gonna be Playstation VS Playstation on YOY again .

It is playstation vs playstation now, along with xbox vs xbox and Switch vs Switch. Which one will actually be up YoY is a competition, but one console doesn't impact the other. 

I think you didn't get my irony.

Anyway, disregard, my irony is off-topic, let's say...

At this point I'm surprised, because PS4 could do better than 2017, and 2019 could be better than 2018 if Sony play very well its cards.

October 27th numbers have been added.

The PS4 and Xbox One are up Week over Week from last year thanks to Red Dead Redemption 2.
The Switch is down drastically Week over Week from last year thanks to Super Mario Odyssey.

November 3rd numbers have been added.

All 3 systems were down WoW this week as the holiday season is now in full swing!
For the Xbox One, next week will be the long anticipated Xbox One X launch week. Expect that 600k+ lead 2018 worked all year to build to almost completely vanish come next week. Honestly, I think 2018 will ultimately be down from 2017 for that system.

For the PlayStation 4, I think the $199 Black Friday Spider-Man bundle has the potential to do equal numbers to the $199 PS4 Slim deal last year. If Sony is extremely aggressive with their marketing and bundling, they equal their holiday season sales of last year if not just slightly exceed them. However, I don't think it'll be enough to stop the PS4 from being down YoY this year.

For the Nintendo Switch, every sign is point to it being up YoY by a considerable margin. Last year, it's 3 major 1st party titles were Fire Emblem Warriors, Xenoblade Chronicles 2, and Super Mario Odyssey. This year, they are Super Mario Party, Pokemon Let's Go Pikachu/Eevee, and Super Smash Bros. Ultimate. Furthermore, Nintendo has many more bundles for the Switch this year (Fortnite, Smash Bros. Pokemon, and Mario Kart 8) than they did last year (.....give a minute....) Whether or not it Nintendo will reach their 20M forecast is another story. But, an increase YoY is all but official for the Switch.

November 10th/Week 45 numbers have been added.

Now we’re really in gear for the holidays as last year, week 45 was the launch of CoD: WWII and the Xbox One X... And unfortunately for the Xbox One this year, it shows.
The lead that it has taken the Xbox One 2018 to build over 2017 throughout the entire year has almost completely vanished. And with the X’s launch last year boosting sales considerably, once 2018 loses the lead, it ain’t gettin’ it back.

For the PS4, this week sees its biggest drop YoY as it is now dangerously close to falling behind by 2 million units. And based on what latest reports and rumors are saying about Black Friday, not even week 47 (Black Friday week ) with the $199 Spider-Man-Slim bundle will do much to offset the loss. Now we’re beginning to see, more and more, that 2017 was truly the peak of the PS4.

Finally, there’s the Nintendo Switch. While it was down once again this week compared to last year, that is insignificant to the fact the next hardware update will have the release of Pokemon Let’s Go. And based on Japan’s media create numbers for that werk the Switch sales for week 46 should skyrocket. Furthermore, with reports just coming in from Nintendo themselves that the Switch had the best selling Black Friday weekend from the 22nd to 26th (Black Friday and Cyber Monday) in the company’s history, even topping the likes of the Wii and DS, the Switch rocketship has completely lifted off and is shooting for the stars in deep space. It’s all but certain that out of the three systems, the Switch will be the only one up YoY.

Switch should be up most if not every week for the rest of the year. Ps4 and xbone will likely be way down on last year. I feel sorry for the Xbox, building up a lead all year then losing it all in a week.

I heard reports of stock issues for the Switch in Japan with the latest Media Create update today. So that may hold it back if it’s true and/or if it’s the same in other regions. But yeah, Switch should be taking off full steam ahead, especially once Smash Bros. comes out.

The latest numbers just got adjusted across the board. However, from what I’ve heard there are still a few more to be made and I’m waiting until they are final before I edit the charts here.