It is a game that takes on a life of its own, untouched by manager or coach, whose influence becomes negligible as form counts for nothing and players often act out of character.
There can be reasons given but no genuine explanation provided for Celtic's 5-1 victory on Saturday. Rangers, who recently scored seven goals against St Johnstone, were expected to gear up nicely for their Uefa Cup tie with Parma while this was a last chance for Celtic to stay in the title race as they trailed their rivals by 10 points.
Dr Jozef Venglos, the Celtic coach, had been the subject of tabloid vilification in the build-up. Here was a man, they claimed, who was too old for the job, a coach who was unable to motivate his players. This was a man who commanded little respect.
For the doctor, Saturday provided a vindication of sorts.
It was a very public vindication at that with the game watched by 90,000 fans as the drawing power of these clubs was made evident; 60,000 packed into Celtic Park and a further 30,000 at Ibrox to watch the action on big screens. For Rangers supporters the occasion became a real video nasty and the few remaining faithful filed out in funereal silence at the final whistle.
The master stroke for Venglos was to team Lubomir Moravcik with Henrik Larsson in the Celtic attack. The 33-year-old Slovakian, who was signed for a mere pounds 300,000, produced the most impressive performance from a Celtic player for several years. He scored twice, giving Celtic an 11th-minute lead with a sweetly hit shot from the edge of the area and his second was a firmly placed header that left Antti Niemi, the Rangers goalkeeper, a spectator.
Little went right for Rangers after a bright start with the sending-off of Scott Wilson for a crude challenge on Moravcik leaving them chasing shadows. Larsson added two goals and young Mark Burchill came off the bench to conclude proceedings in the last minute.
Giovanni Van Bronckhorst's goal from a free-kick at 3-0 down barely registered. The margin of victory was Celtic's greatest against Rangers since 1966 and the emergence of the team that was to conquer Europe. But, amid the celebrations, the brutal fact for Celtic supporters this morning is that there is a seven-point deficit between the clubs. Dr Venglos cannot live on one good result.
"Hopefully we can build on this. We played with spirit, passion and determination and we'll need that in every game from now on," he said.
Goals: Moravcik (11) 1-0; Moravcik (49) 2-0; Larsson (51) 3-0; Van Bronckhorst (53) 3-1; Larsson (57) 4-1; Burchill (89) 5-1.
Celtic (4-4-2): Warner; Boyd, Mahe, Stubbs, O'Donnell; Donnelly (Hannah, 79), Lambert, Riseth, Mjallby; Larsson, Moravcik (Burchill, 82). Substitutes not used: Brattbakk, Annoni, McCondichie.
Rangers (4-4-2): Niemi; Porrini, Hendry, Wilson, Numan; B Ferguson (I Ferguson, 74), Van Bronckhorst, Wallace, Kanchelskis (Vidmar, 61); Albertz (Durie, 61), Guivarc'h. Substitutes not used: Nicholson, Brown.
Referee: W Young (Clarkston).
Sending-off: Wilson. Bookings: Celtic: Stubbs. Numan, Hendry.
Man of the match: Moravcik.