Australia's unprecedented 15 straight test successes may not guarantee the current players their contracts.

Perverse as it may seem to New Zealand fans former Aussie great Greg Chappell wants younger players introduced to the test arena with the experienced brigade including the likes of the Waugh brothers eased out.

Chappell has been quoted in the weekend edition of the Sydney Morning Herald as saying Australian cricket is in danger of going down the English path of only considering seasoned test candidates.

He says the Australian way has always been to "rush the super-talented into test cricket early, preferably before the age of 23".

Chappell backs his views by listing Australia's top 15 batsmen of all time, none of whom were older than 24 on debut - the bulk being 22 or younger. He says batsmen in the 19 to 23 age bracket are "fearless and believe they can player forever.

"They are also young and exuberant enough to withstand the knocks that inevitably come along early in a test career, and they're malleable enough to adjust their game to suit the test environment".

Chappell believes that once 25 or older players can hear the clock ticking and begin to experience self-doubt.

"They know their time is limited which tends to make them lower their sights and play more conservatively". He cites England's Graeme Hick as a prime example of a player who suffered through having to wait.

Food for thought for the New Zealand selectors?

Debut ages of Australia's top test batsmen:

(Rated by batting averages; 2000-run minimum)

Player        Debut age   Tests    Runs   Average
DG Bradman        20        52     6996    99.94
GS Chappell       22        88     7110    53.86
SR Waugh          20       132     8722    51.01
AR Border         23       156    11174    50.56
RN Harvey         19        79     6149    48.42
KD Walters        19        75     5357    48.26
WH Ponsford       24        29     2122    48.23
SJ McCabe         19        39     2748    48.21
WM Lawry          24        68     5234    47.15
RM Cowper         23        27     2061    46.84
RB Simpson        21        62     4869    46.82
RT Ponting        20        39     2475    46.70
AL Hassett        24        43     3073    46.56
DM Jones          22        52     3631    46.55
AR Morris         24        46     3533    46.49