Vasily Vasilyevich Smyslov March 1921 – 27 March 2010) was a Soviet and Russian chess grandmaster, and was World Chess Champion from 1957 to 1958. He was a Candidate for the World Chess Championship on eight occasions (1948, 1950, 1953, 1956, 1959, 1965, 1983, and 1985). Smyslov twice tied for first at the Soviet Championship (1949, 1955), and his total of 17 Chess Olympiad medals won is an all-time record. In five European Team Championships, Smyslov won ten gold medals.
Smyslov was known for his positional style, and, in particular, his precise handling of the endgame, but many of his games featured spectacular tactical shots as well. He made enormous contributions to chess opening theory in many openings, including the English Opening, Grünfeld Defence, and the Sicilian Defence. He has a variation of the Closed Ruy Lopez named for him: the line runs 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Be7 6.Re1 b5 7.Bb3 d6 8.c3 0-0 9.h3 h6. In the Grünfeld Defence, the continuation 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qb3 dxc4 6.Qxc4 0-0 7.e4 Bg4 8.Be3 Nfd7 is known as the Smyslov Variation and remains a major variation. Smyslov also successfully revived the Fianchetto Defence to the Ruy Lopez (1.e4 e5 2.Nf3 Nc6 3.Bb5 g6) in the 1970s, which is now also known as the Smyslov Defense. In the Slav Defence, the side line 1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.Nf3 dxc4 5.a4 Na6 is named the Smyslov Variation. SOURCE: https://en.wikipedia.org/wiki/Vasily_Smyslov
In this incredible endgame Smyslov shows his arch-rival Botvinnik how to win a Bishop vs Knight endgame after Botvinnik fails to find the correct drawing method, even with an adjournment allowing him to analyze the endgame overnight.