Chang Kai-Hsin 4p vs Rui Naiwei 9p: Full game record

Full comments are included in the attached game record.

The Women’s Individual Go event is heating up, as we enter the second half of the 2014 SportAccord World Mind Games in Beijing. We take a look at how Rui Naiwei 9p secured her place in the semi-final, which is to take place this afternoon.

Rui Naiwei is widely considered to be one of the strongest female players in the world. She has lived and worked in many countries, including Korea, the United States and Japan, where she studied under Go Seigen. Rui has won countless titles and just missed out on first place here in Beijing two years ago, losing to Li He in the final.

Her opponent Chang Kai-Hsin 4p has seen much success over the last ten years in Chinese Taipei. She says she has a ‘love-hate relationship’ with Go, with her most memorable game being a half-point loss in a title match final.

The game began with Rui Naiwei showing her intention to build a trademark moyo with moves 24 and 26. Chang’s move 37 was a little strange, leaving a weakness that Rui was soon to exploit. A kosumi on the third line would have been more natural. When Rui came in at the top with move 46, Black could not find a good local reply and so moved into the centre. The game is already good for White at this point, as Rui has a potential splitting attack that will ensure that the moyo on the left side is turned into territory.

Moves 75 and 76 were a bad exchange for Black, increasing White’s lead. It was better to cut, allowing Black either to develop eye-shape or to squeeze White. The position should now have been easy for Rui to convert to a win, but now followed a number of unusually slack moves that gave Chang a chance to get back into the game.

Diagram 2: What happened in the game

Diagram 3: A missed chance to keep Black eyeless

After Chang’s move 81, Rui chose a knight’s move (A in Diagram 2) but the sequence in Diagram 3 is better. White has already invested the two marked stones in Diagram 2 to attack Black’s central group, but this slack move allowed Black to easily make two eyes, rendering those stones ineffective. Black perhaps felt she was behind, as she tried the slightly risky hane at move 85, which left the potential for a ko in the top-right corner. But Rui failed to take advantage of this, playing a bad aji-keshi by capturing on move 104 that removed the potential for ko. It seems she was afraid of lacking ko threats, but nonetheless it was too early to make this play.

Defusing the ko allowed Black to pull back with move 107, a strong move that would not have been possible while there was still the possibility of ko. White suddenly became rather thin and it was now difficult to win cleanly, especially after missing the change to start a ko at move 136 (see variation in attached game record) that would have been very dangerous for Black.

In the end Rui was able to connect up all her groups and reach a winning endgame. She will face Kim Chaeyong 2p this afternoon in the semi-final.

– John Richardson based on commentary by Michael Redmond 9p