The saviour of the hapless and the accident-prone - assuming they have access to a calculator - is: ((U+C+I) x (10-S))/20 x A x 1/(1-sin(F/10)).

Dr Keelan Leyser, a London-based economist who also performs as a magician, the psychologist Dr David Lewis, formerly of Sussex University, and a consultant mathematician, Philip Obadya, also based in London, worked out the formula after studying the experiences of 1,000 Sod’s Law victims and also helpfully came up with a seven-step guide on how to perform the calculation.

The formula looks at five factors relating to any event or action: urgency (U), complexity (C), importance (I), skill (S) and frequency (F).

A score of between one and nine is applied to each of these factors, with a 0.7 score for aggravation (A), and then the formula can be used to find a Sod’s Law rating of between zero and ten.

The higher the number, the more likely it is that someone will fall foul of Sod’s Law.

Apparently it works too