Possible inaccuracy The article says another way to think of it is that the order that the leaves would be visited in a depth first search must be the same after the operation as before Correct me if I m wrong but I believe the order of visiting the leaves in a DFS after the rotation will change but the in order traversal will remain the same DFS traversal before right rotation QPABC DFS traversal after right rotation PAQBC In order traversal before right rotation APBQC In order traversal after right rotation APBQC