Even if SEN is the better team (which is debatable), everyone has to admit that NRG is heavily favored in this series.
Consider maps,
NRG has shown Breeze, Ascent, Sunset all of which they won without showing anything deep strategically. They've banned Bind twice, but likely have something prepped on that map as well.
SEN has shown nearly everything on Split, Ascent, Bind, Lotus, Breeze, and Sunset. They've so far permabanned Icebox.
Ascent and Breeze, the maps that NRG has picked into, were also the two maps that SEN has looked the worst on.
Assuming NRG bans Split, by far SEN's best map, they should be incredibly favored on every other map in the pool. It will be very VERY hard for SEN to win this match, but it's not impossible.
I'm guessing map picks and bans will go like:
SEN bans Icebox
NRG bans Split
SEN picks Sunset
NRG picks Breeze
SEN bans Ascent
NRG bans Lotus
Bind remains