But then a single kick, touch or refereeing call might bring everything crumbling down.

WSJ: The Magic Behind Manchester City's 3-2 Win Over Tottenham

The visitors enjoyed plenty of possession in the second half but did not even earn a single kick at goal, two missed drop-goal attempts from long range by Derrick Hougaard the only time they threatened to get on the scoreboard.

BBC: Wasps 9-0 Saracens

It can lead to the game-changing award of a penalty kick, probably the single most momentous refereeing decision in any sport.

ECONOMIST: Cheating in sport