Not saying it's wrong, but there is a good sized camp (perhaps equally sized) that has it at the ribcage rather than the hip. I agree with Dave Bailey that it is important in all dance forms, though it is probably safer to make assumptions in ballroom. I still find it incredibly beneficial in ballroom to be able to sense which foot my follower is on. And I also think the reverse is just as beneficial (the follower knowing which foot the leader is on). As well as to be on one foot while placing the follower on the other (I confess that my capability in "cross-system" is thanks mainly to some (sadly) limited encounters with AT ). BTW, in my experience, there can be a decent bit of cross-system in the American smooth ballroom dances (perhaps more than in International standard). I think NZ_Guy is referring to a lack of body flight and swing in Argentine tango. I don't know AT well enough to say for sure, but if you can take just about any step in any direction at any time, it's a good sign that there is no body flight/swing. Ballroom tango lacks body flight/swing and therefore has a great deal of flexibility as to direction/timing, unlike waltz, foxtrot, and quickstep.