Howard Raiffa (/ˈreɪfə/ RAY-fə; January 24, 1924 – July 8, 2016) was an American academic who was the Frank P. Ramsey Professor (Emeritus) of Managerial Economics, a joint chair held by the Business School and Harvard Kennedy School at Harvard University.
[2] He helped found and was the first director of the International Institute for Applied Systems Analysis.
[3][4] After service in the Army Air Forces during World War II, Raiffa received a bachelor's degree in mathematics in 1946, a master's degree in statistics in 1947 and a PhD in mathematics in 1951, all from the University of Michigan.
(Assume you are fairly ignorant about martial arts and would have great difficulty making a choice of whom to bet on.)
So, by the axioms of substitutability and transitivity for utilities, they should also prefer to bet on the boxer than on Gamble B.