You had mentioned about the hooded port bit and not having much experience with them. The hooded bit is kind of a mid way between a ported bit and a spade. As you know a spade if used incorrectly can be down right dangerous. With the hooded port you have a good bit for the rider that isn't quite at the point where they can ride a bit without hurting the horse or themselves but they can start learning the basics of a spade bit use. The roller ,or cricket, as it's sometimes called is there to encourage the horse to pick the bit up. Instead of the bit just kinda hanging in the mouth like happens with alot of bit , These and the spade bit you want the horse to actaully hold with the tongue and "pick it up". If the horse is rolling and playing with the cricket he is soft throughout his mouth and ultmately his whole body. There fore he is more likely to pick up on the subtle cues of a spade bit or in this case the hooded port. It has the copper hood to promote saliva production and to kinda fill in the tongue relief. Making it easier again for the horse to "pick up" bit. It is still a fairly advanced bit for horse and rider and when moving a horse into this bit it is usually used with the two rein vaquero style of transition. Which is a rawhide hakamore and the bit in cojunction. When you start out you will use the hackamore 99 perent of the time and slowly work toward the bit more and more until ultimately the bosal is no longer needed. Just like the spade bit.