Shogi opening sequences

Below is a list of the more common initial opening move sequences found in professional shogi games.

Out of the 64,046 recorded (mostly) professional games on Kyokumenpedia (局面ペヂィア) as of 2019 Jan 23 spanning the timeframe from the 1600s to 2018, 77.2% started with a bishop pawn opening (P-76) and 20.8% started with a rook pawn opening (P-26).^[1] The rook pawn push naturally leads to Static Rook openings; however, it is possible to play a Feint Ranging Rook as well. The bishop pawn push is more flexible and thus more ambiguous about the planned opening information given to White.

A less common first move (1.6% of Kyokumenpedia games) is the king's pawn (P-56). This move often suggests a Ranging Rook opening (Central Rook or Opposing Rook) for Black.

Other first moves are relatively rare and occur less than 0.5% of the time. For instance, the fourth most frequent move is the left edge pawn (P-96), but this only occurs less than 0.1% of the time.

Just as the most common first moves are 1.P-76 and 1.P-26, the most common first move responses by White are also the rook pawn and bishop pawn pushes.

Out of professional games with the bishop pawn push as the first move (1.P-76), 56.4% had White respond by advancing their bishop pawn (...P-34) and 42.5% responded by advancing their rook pawn (...P-84).

All other second moves (e.g. ...G-32) occur less than 1.1% of the time.

The ...G-32 choice prevents White from making a Boat castle, which is a standard castle used for a Static Rook position against a Ranging Rook opponent, since the Boat castle requires the king to the 32 square while the left gold remains on its starting 41 square. Thus, this move seems to invite Black to play a Ranging Rook position in order to exploit White's more limited piece development. Nonetheless, if Black chooses a Ranging Rook opening, White's gold on 32 can still be used to develop a Silver Crown castle or if Black plays a Bishop-Exchange Ranging Rook opening White can develop a Fortress castle in response with the gold in this position.

Out of the rook pawn (1.P-26) first move games, 50.8% had a rook pawn advance as White's response and 48.7% had a bishop pawn response.

All other second moves (e.g. ...G-32) occur less than 0.5% of the time.

Out of the central pawn (1.P-56) first move games, 65.5% had a bishop pawn advance as White's response, 30.2% had a rook pawn response, 2.5% have silver to 62, and 1.2% advance the central pawn.

All other second moves occur less than 0.6% of the time.

Advancing the left edge pawn is an uncommon first move that like other more common first moves is usually followed by a bishop pawn (64.2%) or rook pawn (17.0%) push.

Less common responses include advancing either edge pawn.

To state it in a different way, the probabilities of these first two-move sequences are shown below along with their log probability. In the adjacent diagrams are the six most common two-move positions.

Sequence	p	ln(p)
1.P-76 P-34	0.4357	–0.831
1.P-76 P-84	0.3283	–1.114
1.P-76 G-32	0.0029	–5.847
1.P-76 P-54	0.0018	–6.331
1.P-76 R-32	0.0015	–6.482
1.P-76 S-62	0.0015	–6.524
1.P-76 R-52	0.0001	–8.870
1.P-76 P-14	0.0001	–8.988
1.P-76 P-74	0.0001	–9.275
1.P-76 P-94	0.0001	–9.275
1.P-76 R-42	0.0001	–9.969
1.P-26 P-34	0.1056	–2.248
1.P-26 P-84	0.1012	–2.290
1.P-26 G-32	0.0007	–7.260
1.P-26 S-62	0.0001	–8.870
1.P-26 R-52	0.0001	–9.121
1.P-56 P-34	0.0103	–4.573
1.P-56 P-84	0.0048	–5.347
1.P-56 S-62	0.0004	–7.848
1.P-56 P-54	0.0002	–8.582
1.P-96 P-34	0.0005	–7.541
1.P-96 P-84	0.0001	–8.870
1.P-96 P-94	0.0001	–9.458
1.R-78 P-84	0.0005	–7.571
1.R-78 P-34	0.0002	–8.502
1.P-16 P-34	0.0004	–7.889
1.P-16 P-84	0.0001	–9.969
1.P-16 P-14	0.0001	–9.969
1.G-78 P-34	0.0003	–8.295
1.G-78 P-84	0.0001	–9.458
1.P-66 P-34	0.0002	–8.428
1.P-36 P-34	0.0002	–8.669
1.P-36 P-84	0.0001	–8.988
1.R-68 P-34	0.0001	–8.988
1.R-68 S-62	0.0001	–9.969
1.R-68 P-84	0.0001	–9.969
1.R-68 P-54	0.0001	–9.969
1.S-48 P-34	0.0002	–8.359
1.R-58 P-34	0.0002	–8.669
1.R-58 P-84	0.0001	–9.681
1.K-68 P-34	0.0001	–9.681

These probabilities highlight how the most common first move from either side are the bishop and rook pawn pushes accounting for over 97% of all games.

Out of the 1.P-76 P-34 professional games, for the third move, Black:

• advances their rook pawn (P-26) 64.2% of the time,
• advances their sixth file pawn (P-66) 20.1% of the time,
• continues pushing their seventh file pawn (P-75) 5.1% of the time,
• advances their left edge pawn (P-96) 3.2% of the time,
• advances their right edge pawn (P-16) 2.5% of the time,
• advances their right silver to the fourth file (S-48) 1.2% of the time,
• moves their rook to the fourth file (R-68) 1.0% of the time, and
• advances their central pawn (P-56) 0.9% of the time.

All other third moves occur 1.7% of the time.

Playing 1.P-76 P-34 2.P-26 results in the same board position as a 1.P-26 P-34 2.P-76 sequence. (See: Transposition (chess).) This is the most commonly encountered 3-move sequence in shogi.

The 1.P-76 P-34 2.P-66 sequence suggests that Black may play a Ranging Rook opening (Opposing, Third File, or Fourth File).^[a]

However, Fortress or Snowroof are also possible.

The 1.P-76 P-34 2.P-75 sequence strongly suggests that Black will play an Ishida opening (Third File Ranging Rook).

Both the 1.P-76 P-34 2.P-96 and 1.P-76 P-34 2.P-1f sequences with the edge pawn push are relatively noncommittal initial moves by Black. Here, it is as if Black is asking White to determine which opening to play. (These moves also recall the shogi aphorism (将棋の格言 shōgi no kakugen): 手のない時には端歩を突け te no nai toki wa hashifu o tsuke "When there's no (good) move, push an edge pawn".)

1.P-76 P-34 2.P-96 can transpose to 1.P-96 P-34 2.P-76. However, 1.P-96 is an uncommon first move, and 1.P-76 P-34 2.P-96 is 38 times more likely than the transposition.