The Chevalier de Mere or Knight of Mere was born Antoine Gombaud. This French writer adopted the title Chevalier for his character in the dialogues he wrote. Since he was educated at Mere he decided to become the Chevalier de Mere. He was considered a Salon theorist who lived during the 17th century. He posed many questions which he believed needed to be solved by fashionable, intelligent people. Despite his written works being known, it is his probability theory which is better known. He was an amateur math guru. He was most interested in the problem of the points.
As an example, if you have a certain number of games you play such as the best of seven where two players are at the table and there is an interruption in the game what would happen? Should the stake be divided evenly or if one player has already won three and the other won one should the stake go to the person with more wins? Given that there would be three games left and a potential for the person behind to win, Chevalier wanted to know if it was fair to pay out more to the winner when the game was stopped. Pascal and Pierre de Fermat also took up the challenge of this question.
Chevalier de Mere was considered a fortunate and unfortunate gambler. There were times he would win and times he would lose. He approached gambling with the concept of probability. Many consider him to be the origin of algebraic probability. The Chevalier was also considered a rake. To be successful as a gambler he would bet small and always on favourable odds. For example he might bet on there being one six in four tosses of a die and win. Yet he would then double it saying that at least one double six in 24 tosses would occur only to lose his small bet.
The Chevalier de Mere it seems was more of a person with the hope of winning based on his amateur thoughts than successful in his gambling career. Still, he did lead many discussions which turned intelligent individuals towards giving better or at least thoughtful answers. There is not a lot on his life before becoming the Knight of Mere. It is unclear, but most likely he came from money. He managed to have a higher education than others would have had at the time.
His published works also helped him continue his life of some leisure. Given his reputation as a rake it is most likely he had several women in his life and would rather enjoy life than be brought down by it. It was around 1650 that Chevalier de Mere suffered the most losses in his gambling. It is known that he lived between 1607 and 1684, making him a rather aged man at the time of his death. It was a time when many did not live past 40, so living almost 70 years meant he had a good life.