Wilhelm Steinitz (1886-1894) --> unknown knight facing
Emanuel Lasker (1894-1921) --> unknown knight facing
Jose Raul Capablanca (1921-1927) --> knights facing left
Alexander Alekhine (1927-1935, 1937-1946) --> knights facing forward
Max Euwe (1935-1937) --> knights facing diagonally inward? (photo of Alekhine with Euwe out of frame only, so inconclusive)
Mikhail Botvinnik (1948-1957, 1958-1960, 1961-1963) --> (sideways facing center, or sideways facing outward)
Vasily Smyslov (1957-1958) --> sideways facing center
Mikhail Tal (1960-1961) --> sideways facing away from center? (photos show other facings, too)
Tigran Petrosian (1963-1969) --> knights facing forward
Boris Spassky (1969-1972) --> knights facing forward
Bobby Fischer (1972-1975) --> sideways facing center
Anatoly Karpov (1975-1985) --> knights facing left
Garry Kasparov (1985-2000) --> knights facing left
Vladimir Kramnik (2000-2007) --> knights facing left
Viswanathan Anand (2007-2013) --> knights facing forward
Magnus Carlsen (2013-2023) --> sideways facing center
Ding Liren (2023-current) --> sideways facing center
Other notable players:
Caruana --> knights facing left
Topalov --> knights facing forward
Nakamura --> knights facing right
Judit Polgar --> see below
I just saw* this picture of Fischer sitting at the board before a game. He apparently was one of those players who likes to face their knight sideways but both facing inwards towards the center...
I wonder if we can build a table based on photographic evidence of each world champ's knight-facing preference?
[Edit: "I just saw" was in 2014, if you are reading this for the first time]