Roar and Dark Horse > Shake It Off and Blank Space, don't get me wrong, but they are much closer in impact than Style > Unconditionally, so Style single-handedly gives Taylor the edge here.
There was no 3 with katy. Unconditional did terribly. Style is not comparable to it.
The winner is Taylor, easily.
Honestly Unconditionally's performance wasn't terrible, it was a hit, just not a mega smash like the other two. It only peaked six places lower than Style.
SIO/BS are just as big (and going to get even bigger) than Katy's 2 songs from 2013. What makes Taylor the winner is Style vastly outperforming Uncle on radio, streaming & downloads.
Unconditional did terribly. Style is not comparable to it. 
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