The Lubavitcher Rebbe ztz"l was going to have a procedure done that required him to be sedated. He wanted to insure that he would wake up in time for Krias Shma in the morning. So he had the procedure done at a time of night allowing sufficient time to sleep and awake in time for the morning Shma. The doctor who treated him KNEW that such an old and not well man would never wake up on time. So - unbeknownst to the Rebbe - he bet a fellow doctor 1,000 dollars that the Rebbe would not awaken on time.
He was so sure that he would win the bet he called home and told his daughter that he has the money she needs for a certain payment at school. It was a sure thing.... 1,000 bucks on the way.
The Rebbe woke up on time for Krias Shma....:-).
When he became apprised of the bet [the doctor told him] he wrote out a check for the doctor for a thousand dollars to reimburse him for his loss. The Rebbe explained "It's not your fault that I am a frummer...."
[Heard from the Tolna Rebbe Shlita - Melave Malka Parshas Chukas 5774]
לזכות רבי אפרים אבא בן מרים שושנה הוא וביתו וכל אשר לו ברכה והצחלה בכל מעשי ידיהם