i am sorry about this, but i haven't got to much time on my hands. if i had some more, i'd get you the link to the thread in which this has been discussed already.
but generally, they say that players start to decline from the early 30's ( sometimes it starts at the age of 30, but usually, declining starts to happen on a regular base as soon as the players hit 32/33 in age)
i might be able to get the link later on to the other thread, but i g2g and i still need to try and read some other forums posts aswell.
Rev