Let me show you a brilliant idea to cope with the bo-gin, devised by Mr. Aono, an authority on the hayaguri-gin.
White: Aono, B in hand 9 8 7 6 5 4 3 2 1 +---------------------------+ |wL wN * wG wK * * wN wL |a | * wR * * * * wG * * |b | * * wS wP wP wP wS wP wP |c | * * wP * * * wP * * |d |wP wP * * * * * bP * |e | * * bP * * bS bP * * |f |bP bP bS bP bP bP * * bP |g | * * bG bK * * * bR * |h |bL bN * * * bG * bN bL |i +---------------------------+ Black: Shima, B in hand Diagram 1. Up to P-9eDiagram 1 shows the Shima-Aono game played on Jan. 24th, 1983, in the Shogi Renmei Cup Tournament(This tournament doesn't exist any more).
His right Silver stationed on 7c, Aono had played P-9d and then P-9e, which was his answer for the bo-gin.
Moves starting from Diagram 1:
1.K-7i S-6d 2.P-3e Px3e 3.Sx3e
Because of the Silver on 7c, Black cannot resort to the sequence: P-3e, Px3e, Sx3e. Then White will play P-8f, followed by Px8f, P*8e P-2d, Px2d, Sx2d, Rx2d, P*2c, R-2h, Px8f, P*8d, Rx8d, B*6f, Px8g+! See for yourself that the Rook on 8d is secured by the Silver on 7c, therefore Black will have to suffer material loss: a Rook in exchange for a Bishop and a Gold.
So Black shifted his King to 7i, then went on to open fire.
Further Moves :
P-7e 4.Px7e P-9f
The last move, P-9f, was what he had in mind all along. If Black plays px9f, then P-8f, Px8f, P*9h, Lx9h, B*6e. White has made a point.
Further Moves:
5.B*7d B*5d 6.R-2f P*7c 7.B-5f S-6e
In order to avoid the Bishop drop on 6e, Black dropped his Bishop on 7d, only to meet B*5d, which shows a shogi proverb "Bishop for Bishop" put into practice. At the last move, S*6e, Black's Bishop was sure to be captured, which revealed Black's Bishop drop was a failure. So, if you don't want this to happen in your game, you might prefer P-9f in the event White plays P-9d, the way they played in the Shima-Habu game. Or you might opt for a waiting game, postponing your attack.
I studied volumes of game records searching for the clue why the Hayaguri-gin was practically dropped from tournament practice, but simply could not find the answer. Indeed, sequential drops of Pawns and (w)S-5e are very effective countermeasures, but they are not so devastating as the B*5d was against the bo-gin. You are most likely to have a very difficult position, but that does not exclude a possibility of your steering the game in your favor. In fact there seems to be a variety of ways to do so.
In these days, the hayaguri-gin is played against the bo-gin, when the player first essays the bo-gin and then turns to the hayaguri-gin as one of the variations from the bo-gin. No one, it appears, chooses the hayaguri-gin from the beginning. I remained puzzled.
I asked this question to Mr. Aono, who is a pioneer of the hayaguri-gin. He answered:
You need the opponent's consent, as it were, to play the hayaguri-gin. This can be explained in relation to the bo-gin. Take my game against Mr. Shima (presented above). White used to play S-6b instead of S-7b, to which Black played K-6h. When White resorted to the reclining Silver, Black played the bo-gin. While White's bo-gin was eliminated because his Silver was unable to come up to 8c, Black managed to form the hayaguri-gin on his part. But now, most players play S-7b, which means White can play the bo-gin if he wants. Therefore, Black cannot play K-6h. So, P-1f would be a sensible move, waiting to see what the opponent is up to. But if White plays P-1d, you wouldn't want to play the hayaguri-gin, would you? To sum it up, White has ways to avoid it. If you resort to the hayaguri-gin from the very beginning, White will play the reclining Silver to cope with it. If you choose to play bo-gin seeing White's P-1d, White may then play S-7c. You'd have to have your own answers to these countermeasures.
So, in order to play the hayaguri-gin, you've got to have an opponent who would say, "Okay, I'll do the same." If the opponent says no? Hours of your investigation will go down the drain. I think that was why the hayaguri-gin became practically obsolete. It's true that the sequential Pawn drops and S-5e are quite menacing, but I believe Black can obtain an even game when White also assumes the hayaguri-gin. White players just avoid playing against the Hayaguri-gin. That's why it isn't played any more.