Maui, let me remind you of the reasons I chose 4 years:
1. That is when AMD launched Athlon, their first processor and socket technology which did not depend on Intel. That changed everything - as long as AMD was a clone company, they were at Intel's mercy.
2. Because of that reason, that is when I started purchasing AMD.
So the choice of 4 years was driven by a watershed product cycle, that is all.