Dr. Blackwell was also the first black tenured professor at the University of California at Berkeley, where he became chairman of the statistics department. A wide-ranging scholar, he was known as an elegant theoretician who made important contributions to a number of fields, especially in statistics and probability.
His analysis of bluffing as a poker strategy, as well as his research on dueling -- using statistics to determine the most opportune moment for a dueler to shoot -- helped establish him as an expert in game theory.
He conducted groundbreaking work on the mathematics of multistage decision-making that has been applied in defense and finance, and he wrote a textbook on Bayesian statistics, a method of incorporating knowledge about past events into predictions about the likelihood of future events.
"I'm sort of a dilettante," he was quoted as saying in "Mathematical People," a 1985 book of profiles and interviews. In 1986, he received one of the most prestigious honors in the field of statistics, the R.A. Fisher award from the Committee of Presidents of Statistical Societies.
David Harold Blackwell was born April 24, 1919, in Centralia, Ill. His father, who had a fourth-grade education, worked for the railroad, and his grandfather ran a store.
Dr. Blackwell taught himself to read at the store by examining the pictures and letters on seed packages.
At 16, he planned to become an elementary schoolteacher and entered the University of Illinois, where, at the time, there were no black professors. Six years later, he had discovered a passion for mathematics, earned a doctorate in that subject and won a fellowship to Princeton University's Institute for Advanced Study.
While at Princeton in the early 1940s, he sent job applications to 104 historically black colleges -- working as a professor elsewhere, he believed, wasn't a possibility.
However, he was courted by Berkeley and was nearly offered a job there until the idea met with protest from the wife of the mathematics department chairman. She was a Texas native who liked to invite the math faculty to dinner occasionally, and she said she "was not going to have that darky in her house," according to Dr. Blackwell's recollection in an oral history interview.
He joined the Howard University faculty in 1944 and became the head of the mathematics department.
While in Washington, he became interested in statistics after hearing a lecture by Agriculture Department statistician Meyer A. Girshick. After Dr. Blackwell challenged one of Girshick's assertions, the two met and became friends and colleagues.
They wrote a 1954 book, "The Theory of Games and Statistical Decisions." It established them as leaders in the burgeoning field of game theory, which uses mathematics to understand winning strategies in situations that can be applied to economics, biology, engineering, political science and international relations.
Dr. Blackwell was again courted by the University of California. He became a Berkeley professor in 1955 and 10 years later was admitted to the National Academy of Sciences. He was a member of numerous other professional organizations, including the Institute of Mathematical Statistics and the American Academy of Arts and Sciences.
His wife, Ann Madison Blackwell, died in 2006 after 62 years of marriage. Four of his eight children also preceded him in death: Julia Madison Blackwell, David Harold Blackwell Jr., Grover Johnson Blackwell and Ruth Blackwell Herch.
Survivors include four children, Hugo Blackwell of Berkeley, Ann Blackwell and Vera Gleason, both of Oakland, Calif., and Sarah Hunt of Houston; a sister; and 14 grandchildren.
Dr. Blackwell taught introductory- through graduate-level courses and mentored 65 doctoral students in his career. "Why do you want to share something beautiful with somebody else?" he said in "Mathematical People." "It's because of the pleasure he will get, and in transmitting it, you appreciate its beauty all over again."
July 16, 2010 © The Washington Post