Board Thread:Versus Debates/@comment-31810758-20170610230007/@comment-31253119-20170614140639

@namikaze Chapter 657 page 10.

Also wiki link http://naruto.wikia.com/wiki/Mangeky%C5%8D_Sharingan but i can save you from searching it and copy paste it here.

the straight tomoe (直巴, choku tomoe) of Madara's and Sasuke's Mangekyō Sharingan[5] grants them fluidity in their movements when fighting.[6] Madara was able to sense this form and later deduced that he and Sasuke must be connected by more than blood.