Equal Power of Attack

So how do you gain equal power of attack at the frog & the tip ... a lot of the answer has to do with the shoulder ... it initiates everything, it has to be loose and you almost throw it into your stroke ... I realized that from watching Tortelier: http://youtube.com/watch?v=VWWbcvlQGm4 ... it gives you a really powerful/sharp attack ... from there it's all about balance and keeping the bow straight ...