Exploring the openings in Schoolbook chess

As of 2022, based on research using Fairy Stockfish with an appropriate NNUE file, for Schoolbook 2.0 (where the king can only move three squares when castling), there are five good opening moves for White: Note that, back in 2009, Joker80 indicated that 1. c4 was winning for White, but Fairy Stockfish with Belzedar’s Capablanca NNUE file shows that 1. e4 is actually White’s best move, and that it's not winning (it's only +0.44 at a depth of 36 ply and seldepth of 41 ply; that’s about 15% of a pawn better than White's best move in standard international chess, so Schoolbook is slightly less drawish with a slightly larger advantage for White in comparison).
Please note that the following notes were made long before Fairy Stockfish with an appropriate NNUE file has updated our opening theory for Schoolbook

Table of contents

  1. An introduction to Schoolbook
    1. How to play Schoolbook
  2. The king's pawn opening
    1. 1. f4 f5
    2. The Marshall Spike
    3. The Nimzoesque Defense
    4. The Sibahi Defense

An introduction to Schoolbook

One of the nice things about chess variant design is that it opens up new fields of opening study to explore. In standard international Chess, many moves on the first half-dozen turns that is not an outright blunder has been throughly studied and explored. Many opening lines are 20 or 30 moves deep. There are little, if any, interesting new frontiers to explore.

Chess variants, however, make it possible for someone to be a trailblazer again, exploring openings that have never been studied before. With computer assistance, this exploration is easier than ever before. In particular, Greg Strong's excellent ChessV program, in addition to being able to play a number of variants, has a "test this position" feature to help facilitate opening research.

How to play Schoolbook

The Chess variant whose openings that this article will explore is my own Schoolbook chess variant, which has the following opening position:

The piece that looks like both a knight and a rook is called a "Marshall" and can move like either a knight or rook. The corresponding knight + bishop piece is called an "Archbishop". Castling is more flexible than in FIDE Chess: The king can move two, three, or, on the queenside, four squares towards the corresponding rook; the rook jump over the kind to land besides it.

Schoolbook is a very tactical game that rejuvinates the spirit of 19th century chess, when tactics were king and bold sacrifices were common. The knights and bishops are in the same positions relative to the king as they are in FIDE chess; this means that many opening patterns in FIDE chess also exist in Schoolbook.

A note on notation: The lower left corner square is the a1 square; the upper right hand corner square is the j8 square. In order to minimize confusion between "i" and "j", and second to the right hand file is called the "I" file instead of the "i" file. When castling, it is sufficient to note only the king's move. "f4" is moving white's pawn in front of the king forward two squares.

The king's pawn opening

1. f4 f5

Just like standard international chess, one of White's best moves is moving the king's pawn forward two squares. This is called the "f4" move in Schoolbook notation. After 1. f4, black has a number of replies, the best probably being 1. ... f5. The game, at this point, can continue a number of ways, including 2. Ng3 Nd6 3. Nd3 Ng6, 2. Nd3 Nd6 3. Ng3 Ng6, or 2. Nd3 Ng6 3. Ng3 Nd6, resulting in the Schoolbook equivalent of the four knights defense:

Another way to continue the game after 2. ... f5 is with the Schoolbook form of the Bishop's opening, 3. Bd4. Black's best response at this point is probably 3. ... Ng6, which results in the following position:

White at this point can defend his f pawn with 4. Nd3 or 4. e3.

The Marshall Spike

If, instead of 3. ... Ng6, black opts for the symmetric 3. ... Bd5, one reply that White has is called the Marshall Spike. This is when either white moves his Marshall to the h3 square early in the game, or black performs the corresponding Mh6 move. The Marshall Spike, when done by white, threatens the h7 square. One reply for black is to move out his marshall to Mh6, which will result the Marshalls being exchanged and Black having doubled pawns. Another reply to the Marshall Spike, which seems more sensible, is for black to defend his h pawn with h6, which results in the following position:


Position after 1. f4 f5 2. Bd4 Bd5 3. Mh3 h6

One interesting dynamic in Schoolbook caused by the Marshall Spike is that it weakens the other player's kingside. Black will most likely castle queenside and white will castle kingside in a game with the above position. This will result in a dynamic game where both sides can use their pawns to attack the other king without weakening their own king's fortress.

The Nimzoesque Defense

Black, naturally, has some other options besides 1. ... f5 when white opens by pushing out his king pawn. One reply is the Schoolbook equivalent to the Nimzowich defense, which I call the Nimzoesque Defense. In this defense, black responds to 1. f4 with 1. ... Nd6. Since the centrally placed archbishop doesn't defend his file the way the centrally placed queen does in FIDE chess, white can not reply by moving his other central pawn forward two squares the way he can in FIDE chess. What white can do, however, is push out his king bishop's pawn, resulting in the following position:


The position after 1. f4 Nd6 2. g4

In the above position, Black can not move out any of his central pawns two squares until he finds some way to defend them. Should black play 2. ... f5, for example, white can simply respond with 3. gxf5 Nxf5 4. e4 and now black has to move his knight a third time in the opening, and white still has control of the center.

Another way white can reply to the Nimzoesque Defense is via 2. Ng3. Greg Strong has analysized this position, and found the following line: 1. f4 Nd6 2. Ng3 f5 3. Bd4 e6 4. Nd3 Bf6 5. Ne5 Mh6. The position obtained from this line is as follows:


Greg Strong's analysis of the Nimzoesque Defense

Here we see that it is black who performs a Marshall Spike; white's best reply is probably h3, although Mh3 is reasonable if White doesn't mind exchanging off the Marshalls and having doubled pawns.

The Sibahi Defense

Another reply that black has to 1. f4 is to start a queenside fianchetto with 1. ... c6. I call this defense the Sibahi Defense, named after Abdul-Rahman Sibahi, who played this defense against me. Here is how this position looks:


The Sibahi Defense

As we can see, in this position black immediately applies pressure on the f pawn with his queen. Unlike many other openings in Schoolbook, the Sibahi Defense puts the queen in to play at the beginning of the game. White's best reply appears to be 2. Nd3, which develops a piece and defends the f pawn.

Black will probably, at this point, fianchetto his queenside bishop with 2. ... Bc7, which applies more pressure on the f pawn. White, at this point, can defend with either 3. e3 or 3. g3. These aren't the only options; ChessV feels white gets compensation for the f pawn if the gambit 3. e4!? is played.

An analysis using ChessV of the positions obtained after both 3. e3 and 3. g3 indicates that e3 is better; while white has more mobility with his kingside bishop after g3, this blocks the key square for his kingside knight and opens white's kingside bishop to harassment should black play Bb6. Here is the position after white defends with e3:


The position after 1. f4 c6 2. Nd3 Bc7 3. e3

Another way black can continue the Sibahi Defense after 2. Nd3 is to have a Sicilian setup with 2. ... d6. White's best reply, at this point, looks to be 3. Ng3, which results in the following position:


The position after 1. f4 c6 2. Nd3 d5 3. Ng3

Should black now apply more pressure on the f pawn with Bc7, white can reply with the e3 defense.