Whether they go the knee or not is all in the way the knee itself is constructed...it's about the angles within the knee, you can tell when you take their foot off the ground, not while their foot is on the ground. I know that I've not explained it very well, cos its difficult to describe in words what we look for...far easier to demonstrate...and I might add VERY seldom wrong, I'll not say never because there is always one that will make a liar of you. So I'm not surprised about the Charlie Chaplin stance with a horse going clean, similarly I have seen quite a few that stand a bit pigeon toed and bang their knees like buggery.Some horses have really surprised me conformation/gait wise. One was Monkey King. I saw him race a few times at Menangle during the 2010 ID & again later in the year at the MM and he seemed to me to go quite clean & he went bloody fast as well...and yet to my eye when I saw him down in the stabling are I thought he stood like Charlie Chaplin in front.