Each properly constructed court should have suitable, well maintained fill material in the "pit" area surrounding the stakes. The purpose for the fill is to cushion and hold the shoe when it lands instead of letting it bounce or slide.
CLAY: Clay dries to unusual hardness, a condition certainly not conducive to good horseshoe pitching, but when kept moist and putty-like, it provides excellent service. Preparation of clay is learned by experience. Too much water will produce "slick", a liquid solution which serves no purpose and keep the clay unmanageable. Too little water allows the clay to crack like a cookie or even harden. When suitably moist, with no trace of slick or cracking the clay will be found to be pliable and soft. Watering dry clay pits should be done by loosening the clay to 4 or 6 inch depth by shovel and adding water (leave clay around the stake for a couple inches to prevent "slick" from building up..."slick" tends to "pump" up around the stake after the clay has been watered excessively). Watering clay pits after they have been used takes only a very light sprinkling of the top surface and then shaving only the top 2 or 3 inches of clay with a shovel and turning it over, thus allowing the water to work on the underside of the clay while the next game uses the freshly turned surface of clay. This kind of maintenance after each game or practice game will keep the clay in excellent condition throughout an entire tournament. When courts are not in use, a light sprinkling and a cover to prevent evaporation and sunlight will keep the court ready for the next time it is used. Tournament directors should have shovels and sprinkler cans available and should tell pitchers if they are expected to maintain courts themselves.
SAND: Moist sand will help reduce the amount of sand knocked out of the pit by horseshoes, but under any conditions, sand filled pits usually need to be dressed nearly every inning by kicking and leveling sand with the foot, after shoes have been retrieved. Tournament directors should ask pitchers to dress their courts accordingly. Pitchers who expect to pitch in clay as well as sand during the year should be forewarned that pitches which land short of the stake and slide on for a ringer in a sand pit will not slide on clay and will remain a short shoe...a bad habit to watch out for.
WHERE TO FIND GOOD CLAY: This varies in every locality....in much of the U.S.A. good 'blue' clay seems to 'grow wild'. In some areas there are local clays equally as good as 'blue' clay...some may even say better? Blue Clay is also known as blue shale and soapstone in some areas. The best characteristic of blue clay is that it does not build up on the horseshoe like some red clays, yet it does not leave a soapy, slippery feel (unless of course you are pitching in 'slick' (clay with heavy water mixture that causes thick, semi-liquid called slick). Good places to find blue clay is in excavations such as rock quarries, strip mines, building excavations, roadway cuts in hillsides, refuse dump earth excavations, etc. It may be seen along roadway cuts or in piles of strip mining overburden. It may have rock hard 'shale' with it which sometimes breaks down into good clay but it is usually cast aside in favor of solid-free clay. If your state does not have any blue clay (ask park departments where they get clay for tennis courts, ask local pottery and brick factories where they get clay) you may need to get it by the truck load from out of state.