The barrel man is the man with the mic. He heckles the crowd, the announcer, the bulls, and anyone else he can think of.
He's going to have been in the sport a lot longer then 6 years to reach the NFR. He'll have started as a teen (or maybe younger), and done some bronc and bull riding. He'll start working as a bull fighter for friends while they're practicing. He'll graduate from there to local rodeos where he'll be working for free but gaining experience. It will take him a couple of years to get in a hundred or so events.
Once he gets good at the local rodeos, the riders and promoters will begin to notice him and he'll be asked to work at regional events. Eventually he'll start working with the national riders. By this time, he'll have learned how to read the bulls. You need to be able to tell which way a bull is going to go, preferably before the bull knows. He'll probably be approaching thirty.
Best of luck,
Jim Clark-Dawe