(1906-1970) Yugoslavian-born US mathematician largely responsible for making the theory of probability accessible to students of subjects other than mathematics through his textbook on the subject. In the theory of limits, he formulated the law of the iterated logarithm.
Feller was born and educated in Zagreb and also studied in Germany at Göttingen. He worked at the University of Stockholm 1933–39. On the outbreak of World War II, he immigrated to the US. He was professor of mathematics at Cornell University, Ithaca, New York, 1945–50, and at Princeton from 1950.
Feller came to the conclusion, early on, that the traditional emphasis placed on averages meant that insufficient attention was paid to random fluctuations. Much of his study of probability theory focused on the nature of Markov processes (a mathematical description of random changes in a system which, for instance, can occur in either of two states). Feller demonstrated the applicability of this tool to subjects in which probability theory had not usually previously been employed; for example, in the study of genetics.
His work is set out in Introduction to Probability Theory and its Applications 1950–66.

(Robert William Andrew) (1918-) US baseball pitcher. He made his major-league debut 1936 and went on to a brilliant pitching career that lasted for the next 20 years. He led the American League six times by winning 20 or more games in a season; he pitched 3 no-hitters and 12 one-hitters and posted 266 career wins. Feller was famed for his powerful fastball and pinpoint control.
Born in Van Meter, Iowa, US, Feller was signed by the Cleveland Indians organization while he was still in high school. He was elected to the Baseball Hall of Fame 1962.