I did my first bracket race this season, and didn't understand bracket racing until I went through 2 of my 3 practice runs lol. I didn't know that I had to beat the other guy to a finish.
My truck would run a 13.3 all out perfect launch every time, but I dialed in at 14.0 to give myself some room for error and I didn't have to leave as hard at the line (10 psi).
If I were to do it again, I would try using a tow tune or middle tune, then if you have a bad reaction time, and your opponent is catching up, or you have to gain on him, you can turn to your big tune to hopefully outrun him.
Towards the end of the track, if you are infront of your opponent, another technique is to tap the brakes and slow down. That gives you a better chance of not breaking out but still beating your opponent.
But that was my first race. I would race on a small tune and take it easy. I uses the big tune because I didn't want spooling issues on the line.