Chagaev had technically great foot-work but not great footspeed (At least not in the realms of Conn and Walcott). He doesn't slide the way Billy Conn does either (An ATG LHW, very much on his toes and shuffling and cutting in and out of directions). In fact, Louis footspeed is faster than Chageov and can be when trying to close the distance. If Chagaev gets laterally, that could confuse and bother Louis a little. But I don't see Chagaev doing effective work, really, just being defensive and distance from Joe. He can't win a fight trying to out-box Louis. He will get cut and chopped down, perhaps getting countered from his own counter. The bottom line is Chagaev for all his mobility and technicality likes to work from within a mid-range, he's not a distance out-fighter by any means. As MN said, he counters within the pocket. Louis matches up better than Chagaev than vice versa as far as I'm concerned.