Why Irfan Pathan has lost pace

Swing bowling has come under intense scrutiny in the recent past due to the expertise of the Pakistani bowlers. Rabindra Mehta, a NASA scientist and former club fast bowler, has done a fair bit of research over the years to understand what it is that affects the movement of the cricket ball.

His findings are presented in a simplified manner in this very engrossing article, in which everything you wanted to know about swing bowling is explained. For instance, I found out that there are three types of swing bowling - conventional, reverse and contrast!

To me, the most interesting aspect of his findings is presented in the following paragraph, quoted verbatim from the article, which may help explain why Irfan Pathan has "lost" pace, and Mohammad Sami is only able to reverse-swing the ball and has to rely on seam movement when the ball is new!! (The emphasis on some phrases using bold type below is all mine).

So what happens at speeds above 70 mph? The boundary layer on the bottom side....begins towards transition, the asymmetry is reduced and so is the swing such that at around 80 mph there is no swing. So if you are unfortunate enough to bowl at around this critical speed, the ball will not swing, no matter how perfectly the ball is released. In a recent conversation with Mike Hendrick, the former England fast bowler, he revealed to me that he always found it very difficult to swing the ball and after all these years, he finally figured out why when he saw our data. Of course one solution is to slow down a bit.