And if you look, the sales were down YoY for the holidays for PS4. Not by much, but still down. The 2.6 million increase YoY was due to sales throughout the year. So the other systems did steal some sales of the PS4 during the holiday. How else do you explain a system having sold YoY 2.6 million more consoles, yet during the business shopping season selling less YoY.

I understand that, but I must say I was surprised Sony didn’t announce a price cut to 249,- at PSX to keep up momentum. Seems they’re rather betting on bundling all those big games, which seems like a smart strategy nonetheless. Next year is packed with system sellers and that includes multiplatform games like RDR2.

People make the mistake of thinking Switch's success will have a negative affect on PS4 sales, when in reality it's not a ps4/xbo situation, they're too different. That it has no affect is proven by the PS4 doing so well this year despite the Switch launching and selling 13m+. Those 13m+ sales had seemingly zero affect on PS4 sales.

They're essentially not in competition, because Switch doesn't take sales away from PS4 and neither does PS4 take aways sales from the Switch.

You can't know that, thus, you don't know what's right/wrong. Suspect? Surely.

Not hard to swallow and it makes sense given the context of demographics. There's a higher chance of the Xbox One stealing sales from PS4. In the other direction, it's also unlikely that PS4 is taking much from the Switch. They are complementary systems.

But the ps4 would have sold more if the switch didn't exist, making your post wrong by default.

Affect each other? Yes. To any significant degree? No. 

I will. If you can point out, as a matter of fact, just how the two affect each other to any significant degree, I'd be happy to look over it. Otherwise, with the PS4 having its best sales to date, despite the launch of not one, but two, pieces of hardware, I'm inclined to stick by the view presented.