& if i may add to that, Batsman dependence on his instincts. If you watch batsmen of 70s and good part of 80s, they had really good hand eye co-ordination and went on to play with gut instinct. This is evident by the way they hooked and pulled fast bowlers and used feet against spinners. These days with heavy bats and good protection batsman almost play like following a script of fixed pattern. I also believe that is one reason why when a genuinely fast bowler who can either swing or keep a tight line (Likes of Shane Bond, Steyn, Brett Lee, Aamir, Johnson et al), can actually trouble batsmen simply by intimidation. Batsmen today maybe better athletes but technically they are a pale shadow of golden era of 70s and 80s batting school. It is like a cricketing equivalent of today's students, who find it difficult to move without internet.