The Polo Pony
If you already have a horse:
Most horses, with the proper polo training, can learn to play polo. Even if your horse is not large or fast enough to compete against 'real' polo ponies in a polo game, a kind-tempered horse that you can use for all those hours of hitting and ball-handling practice is priceless.
Before introducing a horse to polo equipment, he or she must be well trained for riding. A prospective polo pony should: neck rein with minimal pressure, work very well off of leg cues (i.e. rate speed and cut very tight circles with leg cues and minimal reining, perform the flying lead change), hold a particular gait without breaking, bucking, kicking, or shying, and work well around other horses.
Once the horse has mastered the basics, he can be gradually introduced to polo equipment. He can be desensitized to the polo mallet by first riding with a long whip or stick for some weeks. As the horse accepts being rubbed all over with it while riding, the trainer can eventually work up to swinging a polo mallet all around and under the horse until he accepts it as normal. Similarly, the horse can be gradually accustomed to a soft toy ball to the point where he can be hit with it while working and completely ignore it.
If you plan to get a horse:
Consider the polo training outlined in "what to do if you have a horse" when purchasing a potential polo pony. Many polo players suggest buying off-track thoroughbreds for polo ponies. If you are considering this option, bear in mind that off-track horses are only green-broken and will require at least 1-2 years of retraining before they can even begin training as polo ponies. In other words, an off-track horse will require 2-3 years of your time before you know how good a polo pony he'll be.
In the meantime, you may want to get a calm, well-trained older polo horse to learn how to play polo on, and then upgrade later. Whichever option you choose, a vet check to ensure that the horse is sound for polo is a very worthwhile expense.
Mounting your horse / polo pony
Before You Mount:
Before you mount a polo pony it's important to check the polo girth and the polo bridle. Your groom will hold the polo pony steady as you mount by standing on the opposite side holding the polo stirrup leather and polo reins.
It's important to be able to mount and dismount from either side, however, usually you mount from the left side of the polo pony / horse. Back in the day when the military wore a sword on their left hip, this prevented the sword from hitting a horse's back.
When you mount your weight pulls the saddle sideways which exerts a force on the polo pony's back. A mounting block will place you about 18 inches off the ground and helps reduce this strain.
Place your left hand on the reins and turn the stirrup iron clockwise to bring its far side towards you.
Place your left foot in the stirrup while your left hand has control of the reins, squarely facing the side of the horse.
Grasp the polo saddle near the pommel (front) with your right hand and use your left leg to rise up.
As you rise, swing your right leg up and over the polo saddle.
Lower yourself gently into the polo saddle, place your right foot in the stirrup, sit upright, and breathe deep.
Gather up your reins by taking up any slack so that you have control of the polo pony.
Move forward a few steps and then recheck the polo girth. It may need tightening since you have now added your weight to the polo pony's back.
Take both polo reins into one hand and move your leg forward, while keeping your foot in the stirrup. Lift the polo saddle flap and pull up on the girth straps to adjust them as necessary.
This is a good time to check and adjust your polo stirrups to a comfortable length.
Sit comfortably balanced in the polo saddle, keeping the polo balls of your feet on the stirrup irons, your toes facing out at about a 40 degree angle, and your heels pointing down.
Remove both your feet from the polo stirrups.
Hold the reins in your left hand and grasp the pommel (front) of the polo saddle with your right hand.
Lean forward and to the right, lift your right leg and swing it over the polo pony's hindquarters, then slide down off the saddle to the ground.
After you dismount, "run-up" the stirrups to prevent them from banging against the sides of the pony or catching on barn doors.
Lift the polo saddle flap and loosen the girth.