some more Monaco hypotheses:
) tilt-rotor: track is constructed on a giant tilted platform that rotates so slowly nobody can detect it, but fast enough so the lead runners are always going slightly downhill.
) cyclone: Stade Louis II is oriented WSW to ENE, with heavy stands on three sides which far overarch the track on the north and east sides, but open on the WSW side. This channels the prevailing west wind into the stadium where it is trapped by the south and east stands and directed counter-clockwise around the track, creating a "constant tailwind" effect.