Vale Tudo Bareknuckle full contact mixed martial art allows striking
the entire body. Only rule is do not bite or poke the eyes. They
even kick the groin.

Bare Knuckle boxing look at Kimbo Slice or Lenny Mc Clean.

The UFC is interesting but uses gloves & has lots of rules.

Muay Thai in the old days did not use gloves.

Muay Thai is the best of the striking arts with the closest to
combat reality.

Streetfighting=
Weapons being used against you, A knife, rock, brick, stick, gun,
broken glass, acid, muliple attackers, Psycopath high on drugs.
There are no referees no one to protect you.
You are in Mortal Danger.
Even fighters like Mike Tyson could be in big trouble in such
situations.