Professional Dangos

Dangos can be found by using pattern search in professional game databases. The following examples have been found in the Winter 2007 release of the GoGoD CD.

3x3 dangos

There are 244 3x3 dangos in the database (out of 50 078 games) including this interesting corner position:

Move 130  

Cho Chikun (B) vs Matsumoto Tokuji (W), 1972-02-10, Black wins by resignation

3x3 dango analysis

Considering symmetries, a 3x3 dango can be created with the 3 moves described here. We are interested in the percentage of wins in each case.

 

When the dango is created by playing at , the game is won in 41% of the cases (83/200).

 

When the dango is created by playing at , the game is won in 38% of the cases (16/42).

 

No 3x3 dango has been created by playing at .
Considering the winning ratios, it doesn't seem a good idea to create such shapes.

3x4 dangos

There are 12 3x4 dangos in the database including this efficient living shape:

 

Takemiya Masaki (B) vs Yamashiro Hiroshi (W), 1986-06-18,19, Black wins by resignation

4x4-1 dangos

There are no full 4x4 squares in the database, but it's possible to find 15 stones of the same color in a 4x4 square in this position:

Move 217  

Rin Kaiho (B) vs Hane Yasumasa (W), 1985-07-25, White wins by 6.5 points

5x5-n dangos

To find bigger dangos, it is necessary to relax the constraints and remove several stones in the 5x5 square. The following example is a 5x5-6 dango (19 stones of the same color in a 5x5 square):

Move 305  

Suzuki Ayumi (b) vs Nakazawa Ayako (W), 2003-12-22, Black wins by 11.5 points

Is it possible to find a better result?