In “An Improved Approximation Algorithm for TSP,” Karlin, Klein, and Oveis Gharan design the first improvement over classical 1.5 approximation algorithm of Christofides-Serdyukov after more than 40 years. Their chooses a random spanning tree from maximum entropy distribution trees with marginals equal to optimum LP solution TSP, then, similar Christofides’ algorithm, it adds minimum cost match...