Convince me that Cleveland Williams...

Williams was not the smartest of individuals, but he had given it his all in both Liston fights and was stopped early both times, and basically knew he could never beat Liston. Plus, Patterson wouldn't fight him either.
Liston of course became the REAL TOP contender in the late 50's, the Patterson-Ingo series tied down the crown from 6/59-3/61, McNeeley vs Patterson 12/61, and Liston vs Patterson 9/62-7/63, plus then Liston vs Ali 2/64-5/65.

People like Williams, Machen & Folley all got muscled out of potential title bouts, and got old.
Though Ingo did fight contender Machen and win, other fights between Ingo/Patterson vs Williams, Machen & Folley, would have have competitive.

Note:
HOUSTON, Nov. 29, 1964 (UPI) —Cleveland Williams, a heavyweight boxer who was critically wounded in a scuffle with a policeman last night, underwent five hours of surgery today. Hugh Benbow, Williams’ manager, demanded an investigation of the incident.

Williams, 31 years old, was listed in critical condition at Ben Taub Hospital, but was “resting under heavy sedation,” attendants said. He was expected to recover and box again (but not until 3/22/1966).

 

This is always going to be the bottom line for people in our position.