This record game between Nikolic - Arsovic (Belgrade 1989), with 269 moves, will hardly be beaten as long as the 50-move rule is in effect. The “Longest Game” is probably the most publicized record in Chess history.  Pilnik - Czerniak were in the ‘Guiness Book of Records’ for many years. Now, it is about to drop out of the top-10, mainly because the 50-move rule has for some time (until 1992) been a 100-move rule, permitting determined players to go on twice as long as before with endings like the dreaded Rook+Bishop versus Rook.   --Tim Krabbé