Bracket racing is. . .
make a couple runs and see how fast you are going down the track.
say your times look like this
E/T 15.035 15.015 15.007
Then competition Starts
Each person writes the time they think that they'll make it down the track
You write 15.0
your goal is to make it down the track as close to this time as possible, or at least closer than the guy in the other lane will run to his time, say they dialed 16.5.
he leave the line first, 1.5 seconds later you leave. if you both make perfect runs you will cross the line at the same time, then it will come down to who had the better reaction time. deal with that later.
you run 15.074 the other guy runs 16.600 you were closer so you won.
the other way you can win is, say you got the same time and the other guy got 16.450 he went "too fast" and "broke out" there fore losing.
Usually it is your best bet to be about 5 feet infront of the other guy at the finish line to make sure;
1. you don't break out
2. you get closer to your time than he does his.
To make it easier to catch someone it is nice to go as fast as possible off the line aka have a good reaction time. the timer doen't start until you leave the line and when you may win by only a few hundreds of a second sitting at the line for a tenth of a second seems like an eternity.
Your margin of victory is determined by the difference in RTs and the time between when you crossed the line.