 According to MCC guidelines for umpires , factors to consider when giving an lbw decision include the angle at which the ball was travelling and whether the ball was swinging through the air . He must also account for the height of the ball at impact and how far from the wicket the batsman was standing ; from this information he must determine if the ball would have passed over the stumps or struck them . The MCC guidance states that it is easier to make a decision when the ball strikes the batsman without pitching , but that the difficulty increases when the ball has bounced and more so when there is a shorter time between the ball pitching and striking the batsman . 
