To clarify, If you have bolt-on hubs you should try for no play or as little as possible when the wheel is off the bike, as it will be the same when mounted. With a q/r you will need a small amount of play when not mounted, which should disappear when on the bike. As long as there is no play and the wheel rocks back and forth when you move the valve stem to 3 o'clock and release I consider it good enough. If the hub either has play or does not move freely the cup or cones could be pitted or unevenly worn. It's even possible to have too many balls installed or the wrong size.
Last edited by cny-bikeman; 12-04-17 at 08:24 AM.