~snip~
However, I have learned a lot with the thread of OP, I don't know that during BC there is a dice game and they already knew it but on my mind, the origin of gambling should be on China.
trading with the lives of slave is probably normal during that time. making both slaves fight so they can have a champ to fight with another champ. these kind of records can be found in the archives. i don't think they call it sports betting during that time.
in the bible, they gamble when David fights Goliath. that should have been one of the history of gambling similar to sports betting but bible i guess is not an appropriate record for sports.