Players sit at the machines they were randomly assigned during tournament registration. When the tournament timer begins, everyone in the session hits the spin reels  button and/or the bonus pop-ups  on their machine and plays for the duration of the countdown.

No, there is no way to predict when a slot machine is going to hit a jackpot or to determine which machine is going to be lucky. Slot machines are programmed to use a random number generator (RNG) to determine the outcome of each spin, and the RNG generates random and unpredictable results.