Kubo took the Kio title from Sato with the score of 3-2 - 5th game of 34th Kio-sen

The 5th game of 34th Kio-sen between Kio Sato Yasumitsu and Kubo Toshiaki(8 dan) was held at Tokyo Shogi Kaikan in Sendagaya, Tokyo, on March 30, 2009. Sato became Sente player as a result of Furigoma. Kubo chose Gokigen Nakabisha. Sato's opening was castling his King with 4 generals which seemed too defensive for me in consideration that he was Sente.. According to post-game discussion, Sato said N*9d at 85th move was the cause of defeat since he had no effective approach to Kubo's King after it went up to 8c. Here is the resignation diagram when Kubo moved back his King from 8d to 8c. There would be no effective approach to Gote's King and Sente had no defense. The possible variations after the diagram would be;

• B*8a R*9i B*9h Lx7h+ Bx7b+ Kx7b N-8d K-6a S-5c+ Rx9h+ Kx9h L*9f R*9g +Rx8i(mate, Replayable by clicking the arrow in the right direction under the diagram)
• B*8a R*9i B*9h Lx7h+ Bx7b+ Kx7b G*7c K-6a S-6c= Rx9h+ Kx9h +Rx8i K-9g +R-8h(mate)

Kubo obtained the major title for the first time in his life with this victory. Congratulation! Sato failed to keep the position of one of the title holders. I hope he would come back to be a challenger against them soon.

Comments

[Nat]

I wonder what would happen if Satou had tried B9b at 103th move? If Kx9b then N*8d then
A) K8c Nx7b+(threatmate starting with +N8b K9c G*9b K8d B*7c) if Gote replies Kx7b G*7c K6a (if K7a then N8b+ K6a, then same continuation) L*5c is a good threatmate again (I think this is Hisshi) removing escapte route through 5b, and blocking the lance with any piece even with a rook does not help prevent a collapse by B*7b if Rx7b +Nx7b mate. However after L*5c I do not see an immediate for Sente's king so this line would mean a win for Gote?
B) If Gote tries K9c after the King-gold fork then Nx7b+ is still threatmate (starting from B*8b; and now, if K9b L*9c, if K8c B7c+ and wherever the king moves +B8d is forced mate) So Gote will have to spend a move to remove the threatmate, but I can't see a good way here. Perhaps this line is winning for Sente as well?
C) K9a N7b+ and the square 8b is under double attack and there is no preventing it from falling by dropping a piece there so escapewith K9b but +N8b forces simple mate again.
D) K8a Loos bad because options like
L*8b
D1) Gx8b
D2) if K7a Nx7b+ Kx7b B*8a then
D2a) K6b G*5c K7a S7c+ G*6a B9b+ is hisshi because both 8a and 8b squares cannot be defended simultaneously
D2b) K6a S5c+ piece*7b P*6b is terribly messy so I haven't been able to read through all of it.

And aside from L*8b other options seem dangerous

So in other words I dont think Gote can capture the sacrificed bishop on 9b while feeling completely safe but advancing to, for example, 8d to protect his important defending silver he would be hit by B*9c another bishop sacrifice. Either way the silver will be lost and Sente will obtain a horse afterwards the simply S7c+ seems dangerous.

Gote's attack seems too slow. (3 tempi required) for comfort

Can you give me a line with a sure win for Sente after B*9b? Thanks.

[takodori]

> Nat,

103.B*9b would be an interesting sacrifice, but Sente's King would be mated if he gave a Bishop to Gote at that time. Here would be the variations after 103.B*9b,

Kx9b N*8d K-9c Nx7b+ R*9i, then after that,

(1)L*9h B*7i G(orB)*8h Bx8h+ Kx8h Lx7h+ K-9g Rx9h+ Kx9h L*9f B(G)*9g +Rx8i(mate)

(2)G*9h B*7i L*8h Bx8h+ Kx8h Lx7h+ K-9g Rx9h+ Kx9h L*9f B*9g +Rx8i(mate)

(3)G*9h B*7i B*8h Bx8h+ Lx8h Rx9h+ Kx9h B*8i Sx8i +Rx8i Kx8i L-7i+ K-9i P*9h Kx9h S*8i K-9g G*9h K-9f G*9g(mate)

(4)B*9h B*7i L*8h Bx8h+ Kx8h Lx7h+ K-9g Rx9h+ Kx9h L*9f B*9g +Rx8i(mate)

(5)B*9h B:7i G*8h Bx8h+ Lx8h Rx9h+ Kx9h B*8i Sx8i +Rx8i Kx8i L-7i+ K-9i P*9h Kx9h S*8i K-9g G*9h K-9f G*9g(mate)

There would be more variations, but Sente's King could not help being mated in any case.