Why were there multiple champions in one year? Several events? Differ sanctioning bodies?
Some were due to multiple events in one year and some I believe were lost during challenge matches.
In the case of Alfredo DeOro, whenever he won a pocket billiard championship, they would take away his billiard title and then the next time he won a billiards title they stripped him of his pocket billiards title, in reality for a 20 year span DeOro should have held the titles to both.
Almost no one beat him , they were just the recipients of the vacated title.