Board Thread:Naruto Discussions/@comment-1043414-20140724205217/@comment-1018594-20140725054946

Technomagez wrote: when pain was sealing the tail beast, didn't he mention that the 9 tails had more power than the other 8 combined, which is why they had to do him last? I think he hinted that each tailed beast was stronger than the previous ones combined, i.e. 2 tail > 1 tail, 3 tail > 1 tail+2tail, etc... So by that logic 1/2 of a 9 tails should be stronger than 1-7 tails combined.

This is true. Kurama itself believed that more tails meant more powers, which is something that the other Tailed Beasts, especially Shukaku, hated it for.