All quarters count. But OSU is a seeming lock for the playoffs barring two losses. The PAC12 and SEC are likely to have 2 loss winners. If Clemson gets past ND, at home, they have a shot at undefeated in a weak ACC. If ND wins that one, they have a shot at undefeated. Unless Baylor/TCU/Oklahoma go into some round robin clusterfuck of W/L thus negating the B12, one of them gets in with 0 or 1 loss. So, to me, you have an undefeated Clemson/ND, a 0-1 loss B12 team, 0-1 loss OSU and, most likely, a 1-2 loss SEC team. PAC12 gets shut out this year with several good teams but no very good teams.
Of course, Clemson/ND could step on their own dicks because both have been known to do that.