A digraph operation called pushing a set of vertices is studied with respect to tournaments. When a set \(X\) of vertices is pushed, the orientation of every arc with exactly one end in \(X\) is reversed. We discuss the problems of which tournaments can be made transitive and which can be made isomorphic to their converse using this operation.
Citation
Gary MacGillivray, Kathryn L.B. Wood. Re-Orienting Tournaments By Pushing Vertices[J], Ars Combinatoria, Volume 057. 33-47. .