As can be seen with strategy 2 and 5 actions there is no chance of getting double breakthrough, though I don't think most want it. There is a 67% chance of getting Green completely however. Whichever strategy we use, it is pretty safe to assume that reducing the action count will decrease the chances of actually succeeding. I've seen 45% thrown out as the total chance we have to breakthrough to green with Start!, and as another assumption that it is the true value I think its a pretty reasonable number to get by reducing the action count by one.