Matt Wuerker for March 06, 2016

2 hours / 4 participants = 15 minutes each.Give them each chess timers, attached to the microphones.When each speaks,- it starts his own timer & mic, but also - stops the others’ timers & mics.When they hit the button, it turns off their own mic & timer.Then get rid of moderator participation.When their 15 minutes is up, they are done.Problem solved.You’re welcome.