Synthetic vs. turf vs. dirt: How surface transitions affect horse racing

Thoroughbred horse racing takes place over three primary racing surfaces: synthetic, turf, and dirt.

When a horse transitions from one surface to another, the impact on their performance can be substantial. Here are four ways surface transitions affect horse racing: 

1. Some horses improve while switching surfaces

Many horses show a strong preference for one surface over others.

Future Hall of Fame inductee Manila lost three of his first four starts on dirt. Then he switched to turf and won 11 of his last 14 starts, including the 1986 Breeders’ Cup Turf (G1).

Analyzing pedigrees can help you determine whether a particular horse will thrive when trying a new surface.

2. Other horses regress with a surface switch

Sometimes horses try an unfamiliar racing surface and run below expectations. Two-time Horse of the Year Curlin was almost unstoppable on dirt, but he was beaten when trying turf in the 2008 Man o’ War (G1) and when tackling synthetic in the 2008 Breeders’ Cup Classic (G1).

Since horses who perform equally well across all surfaces are uncommon, if a horse has shown strong form over one surface, it can pay to be skeptical of their chances when transitioning to an unfamiliar surface.

3. Some surfaces are faster than others

Not all racing surfaces are equally fast. Most North American time records have been set on turf, which generally yields quicker times than dirt and synthetic.

Even seemingly similar surfaces can differ in speed. The dirt track at Emerald Downs is much faster than the dirt track at Oaklawn Park.

A horse may appear to run a faster or slower time as they transition between surfaces. It may have nothing to do with their performance and everything to do with surface speeds. Brisnet Speed ratings compensate for the differing speeds of racing surfaces and help you avoid confusion when comparing raw times.

4. Different surfaces can favor different running styles

While there are exceptions and variations from day to day, different racing surfaces can favor horses with different running styles.

Dirt is generally considered a speed-favoring surface. Synthetic, on the other hand, has a reputation for playing kindly toward late runners. A deep closer transitioning from dirt to synthetic may run an improved race if the synthetic surface is more conducive to his style.

Remember these four points, and you’ll be ready to make informed bets when horses transition between synthetic, turf, and dirt surfaces.