Battlefield removal (or BFR) is the reference to the act of one character forcing their opponent out of the established fighting area making it a default win (automatic win).
If the battle arena has established physical boundaries that the fighters aren't allowed to cross, then a BFR can be achieved by forcing the other person to cross those boundaries to win.
- Superman punching Goku out of bounds.
- Hulk throwing Loki out of bounds.
- Shishu using his sharingan genjutsu on itachi causing a possession to make him cross the boundary.
If the battle field doesn't have a established physical boundary, achieving a certain BFR is tougher and less likely, but not impossible. Generally, it's done by trapping the other person in another time or dimension.
- Kaguya/Obito/Kakashi using kamui/space-time ninjutsu to transfer someone into their dimension.
- The Beyonder forcing/making someone go in his beyond realm where he has absolute authority.
- The Doctor forcing/causing someone into a time loop.
- Physical contact with Uboa makes them get transfered to his Universe