I forget which map it was, but Battlefield: Bad Company 2 had a particularly broken area where a medic class (machine gun and 4x scope) and assault class (ammo drop) could pin down the opposing team at their spawn point, from a distance, indefinitely.

Took me and a buddy around a minute to find it, so we weren’t doing something particularly unusual.

Good design could have rendered this tactic inoperable. I don’t know if it ever came.