I would guess that's a Saddlebred. Can't they be shown both three gaited and five-gaited.
Standardbreds are the ones that pull those little carts at the harness tracks. They either race at the trot or the pace and are disqualified if they break gait. They actually have the same ancestors as TWH's. The word Standard in the breed name came from the fact that in the beginning, they could only be registered if they could trot a mile under a standard time. If I remember right, Twist did a mile at 1:58, pacing. He also has an endurance record of one completed ride, 25 miles in 2 hours and 8 minutes. That's quite fast, but five others were faster. Nanc?
