  We extend a technique for lower-bounding the mixing time of card-shuffling
Markov chains, and use it to bound the mixing time of the Rudvalis Markov
chain, as well as two variants considered by Diaconis and Saloff-Coste. We show
that in each case Theta(n^3 log n) shuffles are required for the permutation to
randomize, which matches (up to constants) previously known upper bounds. In
contrast, for the two variants, the mixing time of an individual card is only
Theta(n^2) shuffles.
