The tension simmered just below the surface and sporadic scuffles broke out, with former England captains Martin Corry and Phil Vickery trading blows and ex-international team-mates Dallaglio and Julian White also squaring up.

BBC: Leicester 9-25 Wasps

Pros have always varied their string tension a little based on the court surface, weather conditions and their opponent's style of play.

WSJ: Roger Federer: With Tennis Rackets, He Strings Them Loose

Siphons, exploiting surface tension, remove a discrete amount of plasma to another chamber, where it is spun again and diluted.

FORBES: Medicine Man