One point in the center is worth ten in the corner

One point in the Center is Worth 10 in the Corner  

Segoe remarks that, even though White has more than 10 points in the corner, Black's ponnuki is better.

(Note: Black has captured one White stone, so the stone count is equal.)

Steve: If Black has made a ponnuki, then surely he has 2 points in the center to compete with the "10" in the corner?

Ponnuki is very lucky  

Here, Segoe says that the capture of one stone at a is better for Black than capturing the corner at b.