After one year he transferred to Princeton to work for John von Neumann and developed the first theorems of core (game theory) in his PhD thesis.
[2] Gillies ranked among the top ten participants in the William Lowell Putnam Mathematical Competition held in 1950.
He returned to the US in 1956, married Alice E. Dunkle,[4] and began a job as a professor at the University of Illinois at Urbana-Champaign.
Starting in 1957, Gillies designed the three-stage pipeline control of the ILLIAC II supercomputer at the University of Illinois.
[14] In 1975, the Donald B. Gillies Memorial lecture was established at the University of Illinois, with one leading researcher from computer science appearing every year.