In cricket, ‘leg theory’ is an outdated term for a tactic that involves bowling at, or just outside, leg stump, where a batsman taking anything other than an off-stump guard stands. The intention is to cramp the batsman, preventing him from swinging his arms freely, so that he has to play the ball with the bat close to his body. Consequently, it becomes difficult to score runs, especially through the favoured off side, which can lead to frustration and rash decision making on the part of the batsman.
Leg theory can be adopted by fast bowlers or slower, spin bowlers but, in either case, the batsman is encouraged to play the ball into the leg side. Accordingly, the tactic is often complemented by an attacking field, with a cordon of close fielders, in catching positions, on the leg side.
Historically, the most potent, and controversial, example of leg theory was ‘fast leg theory’, a.k.a. ‘Bodyline’, which was developed by England captain Douglas Jardine for the Ashes tour of Australia in 1932/33. To curb the scoring potential of Donald Bradman, widely regarded as the greatest batsman of all time, Jardine utilised the pace and accuracy of opening bowler Harold Larwood to bowl fast, short-pitched deliveries that bounced into the chest of the batsman.
The batsman essentially had the choice of taking evasive action, exposing his wicket or risking painful injury – Australian wicketkeeper Bill Oldfield retired hurt with a fractured skull during the third Test at the Adelaide Oval – or defending himself with the bat and risking being caught out. The Australian Board of Control for International Cricket subsequently complained to the Marylebone Cricket Club (MCC) about ‘unsportsmanlike’ tactics, Jardine threatened to withdraw his team and, eventually, the intervention of Australian Prime Minister Joseph Lyons was needed to calm the situation.