Most of us here in SPCNet consider Guo Jing and Yang Guo to be around the same level by the end of ROCH. And that level is what we call "Greats-level".
But Yang Guo too A LOT LESS years than Guo Jing in order to reach that level...
...so
Why did it take Guo Jing more years to achieve the same results as Yang Guo?