Before the Reptile realised that right arm medium pace bowlers are ten a penny in club cricket, he used to purvey precisely that action. With a short run up, whippy arm action and a bit of luck, I used to be able to swing the ball round corners, but only ever out. The reasons for this were entirely in my action: wrist position, left arm and so on. Armed with this experience I can tell you that most of the opinions regarding the ball-tampering saga are nonsense.
Take this
article by Saad Shafqat, in which he says, basically, that to call it reverse swing is to be part of a western imperialist hegemony - suggesting that 'normal' swing is only present in English conditions. The fallacy about reverse swing is two fold. The first is that it is "just another sort of swing bowling" the second is that if England could do it last year, it means that any accusation of ball-tampering against Pakistan in racist.
Reverse swing can normally only happen if three factors are present. The ball must be scuffed on one side, and maintained on the other; the ball must be absolutely dry; and the bowler must be bowling at 90 mph+. If any of these three is absent the ball should not naturally reverse (that's why I never got it to, natch). If reverse swing does happen with a medium pacer, the condition of the ball has to be extreme. If it happens on a wet outfield, a similar suspicion is aroused. When these circumstances are combined the ball, if pitched up, will swing sharply, late and the opposite direction to what the batsman is expecting.
Last summer in the Ashes three of the England bowlers were proficient at reverse swing: Jones, Harmison and Flintoff, with Jones and Flintoff being markedly the best. The Australians enjoyed sporadic success with Brett Lee and later Shaun Tait, but no-one else.
The reason Jones and Flintoff regularly got the ball to go was that they bowled a consistently fuller length than Harmison or Lee. The other bowlers, McGrath, Kasprowicz and Hoggard, were simply too slow to reverse the ball. This largely explains why England were better able to exploit reverse swing than Australia. There is another point. Last summer was mainly hot and dry, with abrasive outfields and hard pitches: the ideal conditions for reverse swing. There were two exceptions: Trent Bridge and the Oval, where damp conditions dominated. In each of these games reverse swing was nullified. In the first Hoggard got wickes with conventional swing; at the OVal Flintoff bounced the Aussies out.
The suspicions about the Pakistanis is that they get reverse swing in conditions that do not quite stack up to the above equation. In the first innings at the Oval, Mohhamed Asif, who bowls mid 80s, started to swing the old ball prodigiously on a grey day with a damp outfield. It was this that alerted officials, and the hasty decision in the second innings was arguably incited by the behaviour of the ball in the first.
Put simply, reverse swing is a natural but limited phenomenon that should only be seen in extremely limited circumstances. These circumstances can be mimicked very effectively by the act of ball tampering, and it is not surprising that, if reverse swing should appear in unlikely conditions, ball tampering will be the assumption of many. And for God's sake don't tell me that's an imperialist approach. Empirical maybe, but not imperial.