I've fallen off 5 times in my riding career, but only one of those times was because of a buck. It was my first ride on Scout, and I insisted on riding in my English saddle. Yeah, idiot move, riding a new horse of unknown training level in the least secure saddle I own. He'd apparently never cantered with a girth tightened before. He got a little excited in the trot and goosed up into a canter, and the girth caught him and he threw a little buck that I wasn't expecting, and I ate arena dirt.
A stubborn horse walks behind you, an impatient one in front of you, but a noble companion walks beside you ~ Unknown