Uneven pieces chess

This variant was inspired by some experimentation with Chess With Different Armies. In that game, most armies (including the unofficial ones) have the same materal distribution as the FIDE army: 4 pieces worth just over 3 pawns each; 2 pieces worth about 5 pawns each and one piece worth 9 pawns. However, one of my first CwDA armies, the Heroic Hybrids, had a much more even distribution of material, with the strongest piece being worth less than two of the weakest piece.

While playtesting the Heroic Hybrids (which are published on ChessCraft alongside the Starbound Sliders here) I noticed that the weird material distribution had an impact on the pieces' ability to trade and how easily defended pieces can be dislodged. It made rare positions in chess where the position is unbalanced but equal (such as after 2 pieces are traded for a rook and a pawn) the focus of the game.

As I find these positions interesting, I made this variant where the starting armies themselves are unbalanced but equal.

Setup

Like in regular chess, each side has a king and queen in the centre of the board, rooks in the corner, and knights 2 spaces away from the royal pieces. The remaining four spaces are filled by: a strong leaper on the a file, a weak leaper on the c file, a melee only piece on the f file and a diagonal rider on the h file.

Pieces

Weaker than tier 1

Pawn: Has the same movement as in FIDE chess, including initial double step and en passant.

Tier 1 pieces

Crab: Moves as a FIDE knight, however it may not make a move that brings it 1 rank forwards or 2 ranks back.

Wazir: Moves 1 space orthogonally.

Tier 2 pieces

Knight: Has the same movement as in FIDE chess

Man: Moves as a FIDE king, but isn't royal and cannot castle.

Bishop: Has the same movement as in FIDE chess. The bishop can only reach light squares.

Phoenix: Moves 1 space orthogonally or exactly 2 spaces diagonally, jumping over any pieces in its way.

Kirin: Moves 1 space diagonally or exactly 2 spaces orthogonally, jumping over any pieces in its way. The Kirin can only reach dark squares.
As the Kirin is the only piece used in this variant that does not have a piecelopedia article, its movement is shown below:

Tier 3 pieces

Rook: Has the same movement as in FIDE chess.

Carpenter: Moves as a FIDE knight or exactly 2 spaces orthogonally, jumping over pieces in its way.

Dragon horse: Moves as a FIDE bishop or Wazir.

Highly valuable pieces

Queen: Has the same movement as in FIDE chess

King: Has the same movement as in FIDE chess, including check and castling. However, the King moves 3 spaces when castling to account for the wider board.

Rules

This game follows all of the rules of FIDE chess, with the following exceptions:

When castling, the king moves 3 spaces instead of 2. The king still cannot castle through check, and the Rook still lands on the space adjacent to where the king was before castling.

Pawns may promote to any piece in its own side's starting array, meaning white pawns can promote to any tier 2 piece, Rook or Queen, while black pawns can promote to any tier 1 or 3 piece, Knight or Queen.

When using algebraic notation, use the following letters: K=King, Q=Queen, D=Dragon horse, O=Carpenter*, R=Rook, B=Bishop, M=Man, N=kNight, P=Phoenix, I=kIrin, C=Crab, W=Wazir, no letter=pawn. If a letter is needed for pawns, A should be used.
*as the carpenters moves form a circle

Notes

Relative piece values (measured in quarter-pawns)

White's first move advantage: 1
Pawn: 4

Tier 1

Wazir: 5
Crab: 6

Tier 2

Kirin: 11
Knight: 13
Phoenix: 13
Man: 13
Bishop: 13
Colourbound pair: +2 bonus if both the Kirin and the Bishop are on the board

Tier 3

Rook: 20
Carpenter: 21
Dragon Horse: 21

Highly valuable

Queen: 39
King: infinite, the game is lost without it.

Total for each side (excluding King): 198 (49.5 pawns, 8 pawns more than the FIDE army)
The Queen, all three tier 3 pieces and the Man can deliver checkmate with assistance from the King. The tier 1 pieces and non-Man tier 2 pieces cannot checkmate with only a King to help them.

Effects of an uneven material distribution

The fact that the individual pieces are unequal (even though their collective strength is the same) means a trade both players are willing to accept is unlikely once the Rooks, Knights and Queens have been traded. This slows down the effect of pieces coming off the board, making the middlegame longer and more complex at the cost of making games less likely to reach the endgame.

The lack of pieces of the same value also makes pieces more liable to getting attacked. For example, in FIDE chess, a defended knight or (unpaired) bishop can't be attacked by anything other than pawns. However, here they can be attacked by more mobile tier 1 pieces. Black isn't safe from this either, as they must unleash their tier 3 pieces early to avoid getting steamrolled, where they can be attacked by white's armada of tier 2 pieces. This relative ease of attacking defended pieces makes the game more aggressive as both sides try to dislodge each-other's pieces.

It is also worth noting that white's first move advantage is compensated for by black having an extra 1/4 of a pawn worth of material. This should result in both sides having roughly equal winning chances.

Opening shenanigans

Both sides start the game with 2 undefended pawns (a and h for white; a and b for black) which could make the opening sharper and trappier.

Last revised by Andrew L Smith.