Go move frequencies

The image below gives the move frequencies in a collection of 49000 professional go games.

One sees that playing on the 1st line is unpopular (in the corners very unpopular), and also the 2nd line occurs less often than average. The 3rd and 4th lines on the other hand occur more often than average, while the entire middle area is almost devoid of structure, with the (5,5) points least popular.

The four corners are not equivalent. Most popular is the (4,4) upper right hand corner, followed by the (4,4) lower left hand corner and the (4,4) upper left hand corner. But the (4,4) lower right hand corner is not very popular - players prefer the (3,4) points.

The right hand side has a popular position in the middle of the 3rd line, unlike the other sides.

The above was after the entire game. Below the progress after 20, 30, 40, ..., 250 moves.