The Benkart-Sottile-Stroomer switching procedure on ballot tableau pairs of partition shape calculates an involution which exhibits the Littlewood-Richardson commutativity symmetry. One may realise this involution through different presentations: as a composition of three Schützenberger involutions; or by using one of the tableaux as a set of instructions to tell the order of the jeu de taquin switches. We give a recursive presentation based on internal Schensted insertions similar to those of Sagan-Stanley on skew-tableaux. This presentation follows from a surprising Knuth-type commutation of the bumping routes.
