YouTube iframe embed not starting in HD

Question

I\'m trying to embed an HD YouTube video but no matter what I try, it only ever seems to load the 480p version.

According to YouTube, embedding an HD video is as sim

Answer 1

Mine wasn't working at all. I tried everything including all these parameters

&hd=1&vq=hd720&quality=high

But it didn't work until I added this parameter:

&version=3