The Reverend Thomas Bayes (1702-1761) was an English vicar and mathematician.

In his Essay Towards Solving a Problem in the Doctrine of Chances he was the first person to formally define a method of inferring the probability of an event occurring based upon the frequency with which that event has occurred in the past.

This Essay was published posthumously in 1763 by his friend Richard Price.
His work laid the foundation of modern Bayesian statistics which attempts to calculate the probability of an event from a consideration of the prior probability of that event occurring together with a consideration of any relevant evidence.

These are the very same Bayesian Inferencing techniques that XMaster uses over two hundred years later.

Thomas Bayes is buried in a family tomb at Bunhill Fields in the City of London which is on the west side of City Road south of the junction with Old Street and which happens, quite by chance, to be just a few minutes walk from the offices of The Royal Statistical Society in Errol Street. His friend Richard Price is also buried there.