~ Huzzah ~
This is apparently some form of medieval cheer. Each side of the
arena rooted for a different Knight. These guys (cheerleaders) holding the
signs would tell the spectators a taunting phrase to yell towards the spectators
on the other side (on his count). The other side would then respond back
with their own taunt. This would go on between each Knights competitive
activity.
Twin Pentax K10 DSLR rig, 2fs, SPM, IrfanView.