I saw a video on the Gray Nicolls YouTube channel with Andrew Strauss and he was talking about bats saying that he really works his bats in and the bat needs to prove itself to become his match bat, he also said in this video that some players such as KP will just take them out of the wrapper straight into a test match. It really depends on the player, it seems that Cook and Strauss were quite superstitious with their bats and tend to have 'lucky bats' that they try and keep going as long as possible however some players aren't too fussy about bats