At the tournament, players will get six puzzles to solve on Saturday, and one on Sunday — progressively more difficult. Rankings are determined by accuracy and speed. The top three finishers enter a playoff with an eighth puzzle on Sunday afternoon, competing for the $5,000 prize. Game challenges are not just fun and games, but serious science that has opened the door to practical applications.

“Games are a great motivator for artificial intelligence — they push things forward,” said David Ferrucci, the I.B.M. researcher who led the development of Watson, the “Jeopardy!” computer champion. “But what really matters is where it is taking us.”

Watson, for example, is being adapted for business uses, first in health care to assist doctors in making diagnoses.

Dr. Ginsberg’s real job is chief executive of On Time Systems, in Eugene, Ore., whose software, used by the United States Air Force, helps in tasks like calculating the most efficient flight paths for aircraft. Some of the statistical techniques in this work are also handy, it turns out, for solving crossword puzzles.

A typical puzzle might have 75 words, and up to 10,000 words in the dictionary with the same number of letters as each word in the space, down or across, for the answer. To narrow its choices, Dr. Fill taps a database of millions of answers and clues. If it spots a match, that is a sure thing.

If not, Dr. Fill calculates the 100 most probable answers, based on a number of factors, including how prevalent one of its millions of crossword-related words is in Google’s directory of the Web.

Dr. Fill can fill in a puzzle in as little as five seconds, but then the program does fit and finish work.