Lee McMahon

In the 1960's Lee McMahon and Bob Ryder developed the McMahon Pairing system to address the problem of severely unbalanced pairings in Swiss pairing tournaments. McMahon pairing is a special case of Swiss Pairing in which different initial scores are assigned to various players. McMahon pairing has become the default choice for amateur Go tournaments in Europe and America. (Chess tournaments all still use the Swiss system.)

Biography

• M.A., St. Louis University
• Ph.D., Psychology, Harvard
• 1963-1989 Bell Labs

In 1970, McMahon was a research department head at Bell Labs who realized the benefits of the new Unix operating system for text processing. He convinced the management to buy a new PDP-11 computer which became an important milestone in the Unix development.

McMahon's contributions to Unix include implementations of sed (stream editor), grep (grep regular expressions), qsort (quick sort) and comm (data networking).

Links

• McMahon tournaments
• sed user manual (1978) by Lee E. McMahon with the classic Kubla Khan example
• https://www.princeton.edu/~hos/frs122/unixhist/finalhis.htm