True, but they sometimes make exceptions. Case Keenum was granted his sixth year with Houston. His appeal case was even worse than a player who sits out a transfer season. He just plain redshirted for one season, and had an injury redshirt season as a senior. I think he won his appeal for two reasons. He was a high profile star player, and he's a devout Christian, the type of "student-athlete" poster boy the NCAA wants so they can cultivate that image. In other words, as with everything the NCAA does, it's all political and largely corrupt.