I noticed two things and do correct me if I'm wrong in this, combination punching from a fast boxer kind of freezes GGG as well as making him go backward tends to drop his offensive output.

Now to be fair, what I mentioned isn't an oddity as most boxers tend do do exactly what GGG did in those cases, seldom few can fight going backward quite well.

So all you need for a competitive fight is a guy who can bang hard enough and punches fast enough to keep Golovkin on his toes and going backward on occasion.