As you might guess, this is a horse racing idiom.
You might say, it's horses for courses meaning different people have different skills or interests.
In fact, it's very true that you need different horses for different courses because some require speed and agility whilst others need big horses with stamina and endurance.
Around this time of year in Aintree, Liverpool, The Grand National takes place. This is one of the highlights of the racing calendar and nearly everyone in the country has a bet on it.
It's a race run over 4 miles and huge fences with as many as 40 runners. Only a handful actually make it to the finish.
Here's the full race of a 1974 classic. And....they're off!