Both “rough and ready” and “rough and tumble” are expressions that came from the sport of boxing.
Rough still means “crude,” so “rough and ready” meant a semi-pro or amateur who, although unpolished and perhaps not as well trained as he should be, was still considered good enough to enter the ring.
If a contest was “rough and tumble,” both fighters had agreed to throw away the rules, which led to a lot of tumbling.
