They Benifit by knowing exactly how the boxer has trained before putting on the bet, rather than putting money on something of an unknown entity, on paper a fighter could be seen as a good bet, but if he hasn't trained 100% or has other issues the gambler doesn't know about then he could lose big. Talking about gambler gyms, the big ones such as PKSaenchai, Sorjorwichitpadriew, Jitmuangnon they are betting big money, Sia Kaek the PKSaenchai owner is betting a million baht plus on a lot of his fighters, there is a thing with the fights today they call Naa Sua, this is something that the big gamblers gyms will have stronger than other smaller gyms as they will be seen to make sure their fighters are trained very hard, well fed etc... And if the gym's Naa Sua is strong then they will be seen as more of a favorite to win, so puting them at an advantage. It is harder now w to run a gym for the smaller owners, the big gamblers have a lot more money to invest and they are more in control of the boxers they are betting on if they are looking after them, plus th added advantage they get due to the suppos d credibility of the gym.