In the chapter "On Batting" Chappell details how at a time when he was still coaching in state cricket (South Australia) and before the internet, he spent "several days in Melbourne, locked in a hotel room with Ian Frazer and Swan Richards watching hours of footage of all the top players. These included Sobers, Lara, Gilchrist, Chanderpaul and more to unlock the human movement elements within these players.
What they found was the fact that all the players shared a virtually identical position at the point of the bowler's release, despite finding all manner of different ways in which to get there.
Chappell describes it as the "active neutral" position. Basically meaning that at the point of release, their weight was mainly on the back foot but with their front foot lightly touching or just off the ground, ready to move forward if required by the early release of the full ball, or back if a delayed release meant the shorter ball.