Mythbuster Monday: Horses Should Have Two Wrinkles on Each Side of Their Mouths to Show Proper Placement of the Bit

On Mythbuster Monday, we tackle a variety of equestrian myths to either bust or confirm. Today’s discussion: Should horses have two wrinkles on the sides of their mouth for proper bit placement?

It’s Mythbuster Monday, where Horse Nation dives into different equestrian myths and provides research-based evidence to either bust or confirm those myths. Today’s topic: Should horses have two wrinkles on each side of their mouths to show proper placement of the bit? Is that rule only for certain bits? Can the two wrinkle rule be detrimental to some horses? Read further to find out!

Myth: Horses should have two wrinkles on each side of their mouths to show proper placement of the bit

Myth or Fact: Myth


Proper fitting tack is a huge part of good horsemanship and optimal performance for horse and rider. Although this is true of all tack, it’s especially true of bits. Problems can arise quickly if a horse’s bit is placed too low or too high in his mouth. Finding the best fit in the horse’s mouth will allow for ideal control and the most comfort.

There is a notion that when using a bit you should see two wrinkle in the horse’s lip behind the bit. This idea originated from the British Calvary after a bridle became loose, causing an accident. This rule is still widely used today. But, is it correct to use the two-wrinkle rule as a guide for proper placement of the bit?


To begin this discussion, I’d like to start with the Facebook post that sparked the article. It was a post made by Quarter Horse News interviewing Dennis Moreland Tack. The post stated that horses should have no wrinkles from the bit, especially if riding in a snaffle.

According to an article by Good Horse, the two-wrinkle rule should not be used. They write that good decisions come from understanding. For proper placement, you must take the specific bit and its mechanics into consideration. No bit should come in contact with the horse’s incisors. With this being said, every horse’s mouth is different and fits differently to each bit. Each individual horse also has personal preferences as to where they like the bit to sit.

This article recommends placing the bit low but clear of all teeth and take note of where the horse naturally positions the bit himself. The result may be one, two, or no wrinkles. The bit needs to be in a neutral position according to his mouth so that if the bit is changed, he will understand the cues with the new bit with little pressure and adjustment to placement.


Pro Equine Grooms also published an article on this topic. They say proper fit is when the bit is placed between a horse’s upper hard palate and its bars. Proper fit of the bit also needs to take the horse’s tongue thickness and palate location into consideration. Instead of going by wrinkles, you should feel in his mouth if the bit is in a spot between the hard palate and bars. Two- or three-piece bits will push up against the palate so adjusting multiple times to see where your horse likes the placement best is necessary.


Western Horseman put out an article titled, If the Bit Fits. This article interviews National Reined Cow Horse Association’s Hall of Fame trainer Don Murphy. Murphy states that perfect placement of the bit will aid in the best results through training. The ability to give clear, subtle cues will allow a horse to progress faster and be less frustrated. He also states that many horses will begin gaping their mouths when placement of the bit is incorrect.

Murphy goes on to discuss how using the one/two wrinkle rule is not the best option to choose correct placement of the bit. Like the other articles referenced, he also provides the argument that each horse’s mouth is of different shape and size. Murphy likes to place his finger in the mouth running it across the bars and tongue. This gives him a better indication if the bit is sitting in a comfortable spot for the horse.

The Best Bits also weighs in on this rule in their article. They state the best placement for a bit is where it is clear of the canine teeth and also clear of the genioglossus muscle (a fan-shaped muscle that lies within and parallel to the median plane of the tongue). Each horse’s mouth is different, so using the two-wrinkle rule may place a bit in direct contact with one of these areas. Proper fitment should be in one of the two prominent palate grooves. This placement should be examined by eye for comfort and relaxation of the horse.


The consensus is that the two-wrinkle rule is not an indicator of proper bit placement. Horses each have different shapes and sizes of mouths. Abiding by this rule that dates back to the British Calvary may place the bit on inappropriate structures and cause discomfort.

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