There is the choice to start with triples or with a rock step, however if you check the above chart where a triple step starts on a 1, 2 you can see that the pattern progresses and wraps back around. The choice of starting with a triple or a rock step does have musical consequences as music has phrasing with hits that often happen on 12, or 24 or 36... This means that dancers who choose to start with a rock step will probably find themselves on a rock step on every new phrase. Those who start with a triple will start with a triple on each new phrase. An advantage of starting with the triple step is that dancers can more easily change their foot work right at the start of the musical phrase.