No simple answer. In many of the great military archery cultures of a thousand years ago and more ago, English, Welch, Korean, Japanese, Chinese, Egyptian, it was normal to draw past the ear. The human body can easily do it if the draw is low, about along the jaw line. And it produced a long power stroke that was helpful in getting good power from low technology simple bows. Some cultures, notably the Huns and Turks developed more efficient bows.
And our modern bows, developed in the mid 20th Century, are efficient with the shorter side of the face and under the chin draws. These permit a solid bone on bone anchor reference which helps with accuracy.
The six o'clock draw seems to be the most stable and consistant in setting the string arm and shoulder. Combine that with good anchor references and we may have the best combination for accuracy and power. - lbg