Simplify the following text for a Grade 10 native English-speaking person.
Original: This theory was supported by host Jeff Probst , when he later admitted that using the purple rock tie-breaker was a mistake at this point in the game , because the formula behind it was impossible to apply fairly with only four survivors left .
Simplified: Probst later said that using the purple rock tie-breaker was a mistake at this point in the game , because the formula behind it was impossible to apply fairly with only four survivors left .