Arnold Sheldon Denker was born on February 20, 1914 in the Bronx.
Arnold Denker learned chess in 1922 at the age of 8 by watching his older brothers play. He began playing against a neighbor, then against his neighbor's nephew, Irving Chernev.
Denker began playing in chess tournaments as a high school freshman at Theodore Roosevelt High School.
In 1928, Denker joined the Manhattan Chess Club as a junior member.
In 1929, at the age of 15, Denker won the New York City individual interscholastic championship. He was captain of his high school team.
In his youth, Denker was a Golden Gloves boxing quarterfinalist and later a boxing manager. He won three successive Golden Gloves bouts by knockouts (welterweight division). He was also a promising young baseball player.
In the 1930s, Denker graduated from New York University.
In 1936, Denker and Al Horowitz shared a room at the Lincoln Hotel managed by a fellow member of the Manhattan Chess Club (Chief Hall). They stayed without paying rent. During the day, Denker and Horowitz would hustle chess games for quarters. Whoever won the most during the day had to pay dinner.
In 1936, Denker took 2nd place at the US Open in Philadelphia, won by Horowitz.
In December 1936, Denker married Nina Simmons. Denker was introduced to Nina by violinist Max Rosen, a member of the Manhattan Chess Club.
In 1937, Denker got a job in a meat-packing company.
In August 1938, Denker won the New York State championship.
In 1939, Denker won the New York State championship.
In 1940, Denker won the first of six championships of the Manhattan Chess Club.
In 1940, Denker played 100 opponents in 7.33 hours. The exhibition took place in Cleveland.
In 1941, Denker took 2nd-4th in the New York State Championship, won by Reuben Fine.
During World War II, he gave exhibitions at military bases and aboard aircraft carriers. He also was invited by the US government to help crack enemy codes.
In 1942, Denker took 3rd-4th place in the U.S. Chess Championship in New York. It was this tournament that the tournment director, L. Walter Stephens, mistakenly declared Denker's time had expired in round 6, when it was actually Reshevsky's time (he was looking at the clock backwards).
In May 1944, Denker won the 5th U.S. Chess Championship. He scored 15 1/2 - 1 1/2 (14 wins, 0 losses, and 3 draws). This is the best result (91%) in US Chess Championship play except for Fischer's 100% record. Denker's 14 wins is the most in any US Chess Championship.
In September 1945, Denker played Botvinnik on top board in the US vs USSR Radio match. He lost both games.
In 1945/46 he took 3rd place at Hastings.
From May 4 to 18, 1946, Denker played and won the U.S. Chess Championship again. He defeated Herman Steiner in a match in Los Angeles with a 6-4 score. The prize fund was $5,000.
Denker once appeard in an advertisement for Camel cigarettes.
In August-September 1946 he took 10th-12th place as Groningen.
In 1946, Denker travelled to Moscow and played Smyslov in the US vs USSR match. He lost both games.
In 1947, Denker wrote "If You Must Play Chess."
In 1948, Denker now had two children and gave up full-time chess playing after playing at Mar del Plata. He took over his meat-packing business when the previous owner died. He became the owner of a food distributing firm in Jamaica.
In 1950, Denker was awarded the International Master title. His USCF rating was 2575
In 1953 Denker was the 5th highest rated USCF player in the US, behind Reshevsky, the Byrne brothers, and George Kramer.
In the 1957/58 US Chess Championship (10th US Championship), Denker took 6th-8th place.
In the 1959/60 US Chess Championship (12th US Ch), Denker took 11th out of 12 (Ault took 12th with 11 straight losses).
In 1970, Denker retired to Fort Lauderdale.
In 1971, Denker began playing competitive chess again.
In 1971, Denker tied for 7th place in the U.S. Open.
In 1981, Denker was made an honorary Grandmaster.
In 1981, Denker wrote "My Best Games of Chess 1929-1976."
From 1983 to 1991, Denker served as FIDE zonal (Zone 7) president and a member of the FIDE Qualifications Committee.
In 1984, Denker started the Arnold Denker Tournament of High School Champions.
In September 1988, Denker, age 74, lost a match against HITECH computer. HITECH won 3 games and drew one game. Denker became the first grandmaster to lose to a computer. This was the first match that Denker ever lost. He never lost a match to a human being. In match play, he defeated Reshevsky, Finem Steiner, and Kevitz.
In 1992, Denker was inducted into the U.S. Chess Hall of Fame.
On November 12, 1993, Arnold Denker's wife, Nina, died at the age of 78.
In 1995, Denker co-wrote with Larry Parr "The Bobby Fischer I Knew and other stories."
In 1995, Denker took 6th place in the U.S. Open.
In 1998, Denker took 3rd-4th in the 5th Space Coast Open. He was rated 2328.
In 1999, Denker took 6th-16th in the 6th Space Coast Open. He was rated 2272.
In 2001, Denker took 3rd-5th in the 8th Space Coast Open. He was rated 2252.
In 2002, Denker took 10th-16th in the 9th Space Coast Open. He was rated 2254.
In 2003, Denker played in the US amateur Team South tournament in Orlando. He won one game and lost one game. His final rating was 2251. This may have been his last tournament.
In 2003, Denker was suffering from brain cancer.
In 2004, Denker was given the title of Dean of American Chess (Helms and Koltanowski were the previous title holders).
Denker died at his home in Fort Luaderdale, Florida on January 2, 2005. He had brain cancer. He was 90.