lets predict how many units the PS4, XB1, switch, Wii u, and 3DS will sell this year in the US.
2016(Without Dec)
PS4- 3.5m
XB1- 3.2m
3DS- 1.8m
WU- 422k
2015
PS4- 5.7m
XB1- 4.92m
3DS- 2.42m
WU- 1.4m
2014
PS4- 4.76m
XB1- 4.32m
3DS- 2.64m
WU- 1.65m
2013
3DS- 4m
PS4- 2m
XB1- 1.92m
WU- 1.2m
2012
3DS- 3.6m
WU- 933K
2011
3DS- 4.1m
Since 2017 will be the 4th full year when the PS4 and XB1 will be the on the market lets compare it to the 4th year of their last-gen counterpart.
2009- XB360- 4.78m
2010- PS3- 4.73m