Chicken Newbie, my Black Wyandottes, rooster?

[DownByTheRiver]

I'm curious what opinions are of male vs. female on these black wyandottes? They are about 3 weeks old. I think I have a future rooster.

Chick 3:

This is the other two chicks:
Chick 2:

Chick 1:

 

[FrankPrize]

I genuinely wouldn’t be surprised if chick 1 & 3 are both cockerels. Chick #3 has a single comb so he’s not purebred.