[MissTargets]

Some of those flat mouth piece bits can be as severe as a ported bit. You figure, that the pressure is right down on their tongue. The port would take some pressure off the tongue and put it on the roof on the mouth. The longer the shank, the more leverage and severity.

Shank length is limited at AQHA shows. Did you ever see riders having to drop their bridles,after performing in reining classes?

[FrogInABlender]

The flat mouth piece bits I have seen still have a port, or arch in the middle for tongue relief. The one in the picture did too, but they had the flat part turned up vertically so you could see it's width and it made it hard to see the port.