The value of two moves in a row

There is a pro game with an unusual situation in which for some time white can play two moves in a row and can choose any time during the game to do it.

Game featured in an article "The Value Of Two Moves In A Row" by Matthew Macfadyen in the British Go Journal, number 90, 1993. It's "one of (his) favourite professional games". I (Malcolm) don't know if we can reproduce Macfadyen's comments, but the game itself should be OK. RBerenguel: the PDFs are now available from the BGA website. Here is he relevant file.

The game is Okumura Yasushi (Black I think) vs Omori Yasushi, in the final of the Shodan section of the 1987 Kisei.

Moves 1 to 10  

Moves 11 to 20  

Moves 21 to 30  

Moves 31 to 40  

Moves 41 to 50  

Moves 51 to 60  

Moves 61 to 70  

Moves 71 to 77  

Black has killed the white stones, but has the threat of two moves in a row to deal with. White ends up resigning at move 252. For the complete game, the sgf is here.

Tasky: why did W never use his 2-moves-in-a-row-privilege? couldn't he have killed the black group in bottomright and doing so saved his group?

MrTenuki: My guess is that White's "2 moves in a row" actually refer to the mannen-ko in the corner-- namely, in the form of a ko threat and its follow-up.