"3 To 1" Rein Hold
In the 3 to 1 rein hold, one hand (historically, the left hand) holds three reins and the other only one rein. The three-rein hand controls both curb reins and the bradoon rein which belongs to that side, and the other hand simply holds the other bradoon rein and the whip. It is a hold that was common to the classical dressage tradition. Today the 3 to 1 rein hold is used while training, rather than competition, although it is still seen used by the Spanish Riding School.
The left hand holds the left bradoon rein below the fourth finger (pinkie), the left hand curb rein between the third and fourth fingers, and the right hand curb between the second and third fingers. It is held right over the pommel of the saddle. The right hand holds the bradoon as it would normally hold a snaffle (between the third and fourth fingers), and the hand is held very close to the left hand. This hold has several important consequences: it decreases the action of the curb, it prevents the rider from riding with their hands too wide or performing an overzealous opening rein with their left hand, and it shows when the horse is not properly straight, because the rider can no longer make the rein pressure on one side of the mouth any stronger than the other, since reins from both sides are held in the left hand. The rider must ride off the seat and legs to bend the horse, and the horse must therefore be properly "through".