According to the NDCA rulebook, which has the final word on what is Bronze/Silver in American Style competitions (excluding closed franchise competitions [i.e. Fred Astaire/Arthur Murray]), the Chase Turn American style is a Pre/Intermediate Bronze step, on which both partners are on opposite feet turning opposite directions throughout the pattern. In the International Style syllabus, The Chase Turn is initiated by a foot change for the man, which puts both partners on the same foot and has both partners turning the same direction AFTER the initiation of the pattern and prior to the end, which presents more of a challenge. So, if this were a competition, it would depend on which style/level you were dancing at that competition. Now, if it is social dancing we are talking about, I feel that either pattern is acceptable as long as you/your partner both execute the pattern to your best ability. The lady's/followers part in both styles remains basically the same, it's the really only the man's/leader's footwork and direction of turn that change. As far as the lock step is concerned, for International Style, there is a lock step. In American Style, it is generally is danced with a Cha Cha run instead of a lock step, however the lock step is acceptable (the lock step when danced in the American Style Chase Turn came from the current International influence to American style Dancing, but may have been danced in the American Style Chase Turn prior to the influence for styling purposes.) This is based on the most current competitive information available, and is not meant to replace any of the historical origins of the pattern. Since dance evolves so frequently, this information could also change.