When I was deeply involved into the very much competitive Championnat de France d'Endurance reserved to Classics, VHC* in our words, we used to say: Do you know the difference between 24 Heures du Mans and 12 Heures du Mans historiques? Simple: after thirty minutes of the 24H race, every spectator knows all the drivers' firstname. After thirty minutes of the 12H historic race, every driver knows every spectator's first name…
(*Véhicules Historiques de Compétition)