What to expect from football's whistleblowers

Out of every six or seven fouls in the Premier League one is punished with a card. Over the last seven seasons fouls per game averaged 22 while cards per game averaged 3.5. So there were between six and seven free kicks for every caution or dismissal.

Over the last 20 seasons, in betting markets where each yellow counts as ten and each red as 25, the average bookings make-up was 37. In the lowest season it was 31 and in the highest it was 43. Last season it was 40.

Referees strive for consistency. Twice a month Premier League referees train together and discuss decisions that provoked controversy. There will always be some variation between officials, however.