The tolerance levels had been set at five degrees for spinners, seven-and-a-half for medium-pacers, and ten for quick bowlers, a situation that invited much criticism from past greats such as Ian Chappell.
But the study, conducted by three prominent biomechanics experts, suggests that the human eye can only detect a kink in the action if the straightening is more than 15 degrees.
.....The biomechanics men - Dr Marc Portus, Professor Bruce Elliott and Dr Paul Hurrion - used cameras shooting at 250 frames per second (ten times the speed of a TV camera) to illustrate phenomena such as adduction and hyper-extension, which can convince an observer watching with the naked eye that the bowler is chucking.
Research was also undertaken during the ICC Champions Trophy in England, where it was found that 13 of the 23 bowlers filmed straightened their arms more than the current permissible levels. Ramnaresh Sarwan, he of the fairly innocuous legspin, was the only man observed who didn't straighten his arm at all.
Based on these findings, the ICC is to extend the tolerance limit to 15 degrees for all bowlers, regardless of whether they bowl at Shane Warne's pace or Shoaib Akhtar's. Match officials will still be expected to note down suspicious actions, and pass on the information to the ICC.
ICC study reveals that 99% of bowlers throw | Cricket News | Global | ESPN Cricinfo