This system is perfect for telephone tipsters or any other tipsters that has or claim to have inside information.
If these tipsters had a good run, then back to lay their horses. The reason being that more people will back their horses and therefore the price will fall giving you the opportunity to lock in profits.
If they are on a losing run which tend to happen quite regular, then just lay their horses. Tipsters who advertise for sale their tips in national newspapers, tend to have a poor record with their horses for winning and price value.