Paul Keres (1916-1975) was a great player from Estonia. He was one of the world’s leading players from the 1930s to the 1960s. Keres won the AVRO tournament in 1938 and became the leading challenger to World Champion Alexander Alekhine, but a match never took place. Later, Keres came in second in four straight Candidates’ Tournaments. In four consecutive Olympiads, Keres won the individual gold medal. Keres won the Estonian Championship and the USSR Championship three times each. He was an important chess writer and contributor to opening theory, including the variation in the game shown. He remains the leading contender for the “strongest player who was not a world champion.”
Gideon Stahlberg (1908-1967) was a great Swedish player in the years when Keres first dsiplayed his talent. They played a match in 1938. After eight games the match was a draw with each player winning two games. This experience helped to prepare Keres for his match with Max Euwe, the former world champion, in 1939-40. Keres won that 14 game match by one point. Stahlberg had match practice with wins against Rudof Spielmann in 1933 and Aron Nimzowitsch in 1934. In the early 1950s, Stahlberg played in two Candidates’ Tournaments. He wrote more than ten chess books.
The selected game is from the Stockholm Jubilee in 1966-67. There were ten players in a nine round round robin. Keres was the clear winner with 7/9 a point and a half ahead of the field. Stahlberg came in eighth place with 4/9. The opening was the English, which begins with 1.c4. Keres played an early e5, which Stahlberg answered with g3 in order to fianchetto his bishop. Keres played c6 to block the long diagonal that White’s bishop would be placed on. That setup is the Keres Variation. Stahlberg permitted Keres to play the cramping d4 and later get control of f3. The result was a dynamic crush by Keres. It may be presumed that Stahlberg was no longer near his earlier strength. Perhaps, he was also not feeling well or even was ill. I have no information on his condition, but he died nearly five months later. Keres died at the same age eight years after Stahlberg.