Z (absolutely unmatable position, by nyanko)

"Z" is very important concept in shogi.
Z means absolutely unmatable position no matter how many pieces the opponent has in hand.
(The name "Z" derives from Japanese "Zettai Tsumanai", which means absolutely unmatable in English.)
For example, the sente king in figure. 1 is in Z. If gote will move G*2h, sente will Sx2h, and +Nx2h is not check. Also, if gote will move B*3i, sente will Sx3i, that position doesn't mate.
When you castle king in Silver Crown, the position like figure. 1 sometimes occur. So in that case, you can apply the concept of Z.

  figure. 1

If your king is in Z, it becomes easy to judge whether you should attack or defense, furthermore you can focus entirly on thinking move of attack. Additionaly, when your king is in Z, there are many cases that you can win even if you won't the best move.

Figure. 2 is my game of 10 seconds shogi, the opponent is amatuer 5 dan.
In blitz game, Z is more effective because it becomes easy to read.
The last move in figure. 2 is P*4g.
What do you move in this position?

 Figure. 2

It's the technique that the Gold in 4h doesn't escape.
When the opponent will move Px4h+, my king in that position is still in Z.
Therefore I could focus entirly in attacking.
So I moved Bx3c+ in figure. 2.
After that, Gx3c, S*2c, B*1c, +Rx3c, Nx3c, N*3e, B*6g, G*5f, R*8b (figure. 3).

Figure. 3

In figure. 3 you can take the Bishop (Sx6g), but it's too pasive, as commonly said that speed is more important than material gain in Endgame.
I moved Sx1b+ and continued attack.

The following is the entire game. Probably my attack is not best way, but my king is Z so that I just had to maintain 2-move clearance of the opponent's king, it was easy to win.
As above, it's effective to keep your king Z and not permit the opponent's king Z.

Example game of Sakata-Opposing Rook (by nyanko)

Here the example game of Sakata-Opposing Rook is shown (the opponent is 4-dan).

This is 10 seconds shogi, so there might be many mistakes and I was in bad position in middlegame.
Afterthat, I holded out and succeeded in turnaround.

（sente．）

（gote．）

Sakata-Opposing Rook (by nyanko)

There are many shogi strategy and they can classified in major tactics and minor tactics. Here I call surprising attack as minor tactics.
In recent years, surprising attack is hardly played by professional shogi player because it is easy to cope with them for strong player. But, for amaturer player such tactics is effective.
I introduce Sakata-Opposing Rook here.
This tactics is said to be one of most famous surprising attacks and this is invented by Sakata Sankichi, who are very strong professional shogi player in the early 1990's.

The opening of Sakata-Opposing Rook is usually played when you are gote. The opening is P-7f, P-3d, P-2f, G-3b, P-2e, B-3c (figure. 1). In this post, figure is turned upside-down for you see from the side of Sakata-Opposing Rook.
R-3c is characteristic move in this tactics.

figure. 1

After that, Bx3c+, Gx3c (figure. 2). Gx3c is also characteristic move.
In figure 1 position, many opponent will move Bx3c+ because G-3c is usulally said to be bad position. If the opponent wouldn't move Bx3c+, you can play Sakata-Opposing Rook by moving Bx8b+ and afterthat G-3c, or Bishop Exchange by moving G2b.

figure.2

If the opponent move K-6h in figure 2, ordinary move is R-2b, but I can recommend B*6e as a small ingenuity (figure. 3). The aim of B*6e is to get one Pawn and attack 2g in the future.

figure. 3

After figure. 3, G-3h, Rx7f, K-7h, R-2b (figure. 4). G-3c and R-2b is the formation of Sakata-Opposing Rook. This tactics attack file 2 with Gold and Rook, and furthermore Bishop in some cases.

figure. 4

As one example of move sequence after figure. 4, P-4f, R-5d, G-4g, P-2d, Px2d, P*2g, R-1h, Rx2d (figure. 5). P*2g attack is made possible by B*6e and get one Pawn and then succeded in break file 2.

figure.5

Additionaly, after figure. 5, G-3h, P-2h+, Rx2h (if Gx2h, Bx1h+), Rx2h+, Gx2h, R*4h (figure. 6). In figure. 6, king-gold-silver fork, so Sakata-Opposing Rook attack is powerfully sucsessful and definetely winning.

figure.6

In fact, this example move sequence is ideal for this tactics with the view of illumination.
However, I can defeat amatuer Dan holder with Sakata-Opposing Rook, so I think this tactics is effecient. If you have interest, let's try it.