User blog comment:Xangr8/But why the important incidences, only 72?/@comment-3535905-20120316112523/@comment-4043223-20120316161316

Sima is correct Xangr8, their are only 48 known pieces but that's not to say that the significance of the number 72 won't be explained further throughout the series. At this point we can only speculate past the things we have learned in AC:B.