A ponnuki is worth thirty points
Especially when played before middle game, a ponnuki in the center can exert influence in all directions. The number 30 here is of course just a manner of speaking - what is important is that it is large. One needs a very good reason to allow one's opponent to get one.
By analogy with the ponnuki proverb, some say that this shape is worth 60 points. Again, one should not take this number too literally, but whatever the value of this position is, it is huge.
-- Andre Engels