In yahoo dominoes, under what circumstance is the first play required to play the biggest double?

I have been playing the game for over 50 years and have never heard of that rule.In yahoo dominoes, under what circumstance is the first play required to play the biggest double?
That's always been the rule. You play big six first or the biggest double that a player has. The only time you would not have to do that is after the first hand has been played.In yahoo dominoes, under what circumstance is the first play required to play the biggest double?
who decides who goes first?....YOU?

the highest double decides who goes first...DUH!!!