I apologize for the sound quality and for my horse’s inattention. It was an extremely windy day and the loud gusts were bothering her, plus she had just been vaccinated (by the evil evil vet with the awful horrible needles), AND there was a noisy tractor running right outside the barn, so she was a smidge upset and distracted. Now, why is the juxtaposition between the two bits’ actions diminished once they are placed in the horse’s mouth? The primary reason is that in this environment, the bit folds slightly along its central joint to accommodate the tongue. This frees this joint, allowing the sides of the black bit to rotate more freely from one another than before. However, keep in mind that this black bit is not a true Tom Thumb. A real Tom Thumb would not have this degree of freedom even within a horse’s mouth due to the tightness at the junctions of all of its joints and the shape of its shanks. Unfortunately for the sake of the demonstration (but fortunately for my horses) I do not own a Tom Thumb, nor could I find one to borrow to make the video. So the clips you get here are imperfect in that regard, as they do not show the severity and total lack of side-to-side independence that you get with a real TT. Notice, however, that while both bits have some movement on the opposite side when one rein is pulled (and almost any bit will have this to some degree, with the possible exception of chain and Billy Allen / Myler mouths), it takes far less pressure on one rein to activate the motion of the black “TT,” meaning that the whole mouthpiece of that bit is rotating and pressing down on the horse’s mouth as a single unit, thus increasing its severity and decreasing its finesse, independent side movement, and total cuing ability.