Choosing the proper mount was of the utmost importance (he had explained). Given a string or stable of horses to choose from, one wanted to pick a mount with a flat back, and yet not too wide-bodied or else it wouldn't be possible to get a good grip with the knees. The wither, or bony hump at the base of the neck, should not be too large (which would make it impossible to lie flat while galloping) nor too small (which gave no purchase for the hands), but somewhere in between. And the horse should be of a compliant disposition, for at some point it was bound to happen that the horse-thief would become disarranged on the horse's back, as the outcome of some bump or swerve, and then it would be entirely up to the horse whether the Vagabond would be flung off into space or coaxed back into balance.