Type a move definition below, and then click
on the move above you want to replace.
Betza string:
To practice a bit with (X)Betza notation you can use this interactive diagram,
which allows you to (re)define the moves for all piece in it,
through the text entry below the piece table.
The diagram supports most of the Betza notation as discussed above;
the modifiers n and j only work predictably on diagonal and orthogonal atoms, though.
It also supports the XBetza extension (but not more than one locust capture per turn).
The new atoms are:
U Universal Leaper (Kraken), can teleport to every square except the one it is on.
O Castling with the piece at the board edge in the given direction.
The range specifies the King step.
C Camel. Synonymous with L.
Z Zebra. Synonymous with J.
X Extended. Suffix to other leaper atoms, and boosts those by 1 orthogonal step (G), 2 orthogonal steps (A and J), or 3 such steps (others). (FX = Giraffe)
I Imitator. All mc (default) or ekd moves of the last-moved piece. A b modifier flips these.
Multi-leg moves (changing mode, range and/or direction between legs)
are defined by joining groups of modifiers for the individual legs by a ('again') modifiers.
(More about a...)
New modifiers, or modifiers with a slightly different meaning on non-final legs:
Lame Leapers, Bent Sliders and Locust Capture
The modifier a can be used to concatenate multiple groups of other modifiers,
to describe a multi-leg move.
E.g. fcafmF must be read as (fc)a(fm)F, and specifies a double move,
the first leg being fcF, which is then followed by fmF.
The 'forward' (f) in the second leg must be interpreted as "in the same direction";
directional modifiers on continuation legs are always specified relative to the direction of the previous leg.
The previous example thus shows a 'locust capture',
i.e. removal of an opponent from another square than where the piece moves to.
The a modifier can also be used to describe bent trajectories,
as the second leg can have its own set of directional modifiers.
E.g. masR = mR followed by sR describes a 'hook mover',
a Rook that can turn one 90-degree corner on any empty square it can reach with a Rook move,
as the s is relative to the first leg, and thus means perpendicular to the left or right.
Another useful application of a is for exactly specifying the path of an oblique lame leaper,
as a sequence of King steps over the squares where it can be blocked.
A.g. the Xiangqi Mao can be written as mafsW,
indicating that it must first step to an empty Wazir square,
and then can continue with a step in the forward-sideway direction, i.e. at an angle of 45 degrees,
a diagonal step.
The Moa would be mafsF, starting with a diagonal step,
while the Moo would be mafsK, as it can start both orthogonally and diagonally.
Such destinctions could not be made with the Betza n modifier.
Betza notation derives its compactness from smart choice of defaults,
making modifiers redundant in the most common cases.
E.g. by default the mode of the move is mc,
and the direction set 'all directions implied by the atom'.
To retain this virtue in multi-leg moves,
we adopt the rule that non-final legs (before an a) by default have mode m,
while continuation legs (after an a) by default move in all directions belonging to the atom,
except back in the direction it came from.
So aK means a double-moving King, but does not include a turn pass (or any locust capture).
e ('en passant') new mode: capture a lame leaper on a squares it just passed through. in and nn moves create e.p. rights.
d ('destroy') new mode: capture own piece.
k ('king') new mode: move can only be used to capture a royal piece (deliver check). (KfkR)
x ('excite') activate a piece without moving, that piece making the remaining legs of the specified move. (mNxaN) If no legs follow, it works in reverse, and borrows the moves from the target piece. (xK)
u ('unload') puts the piece that the entire move captures on the initial square. (udQ = Swapper)
p ('hop') in non-final leg: leg ends on an occupied square, without disturbing the contents. (mRpafscR)
g ('grasshop') in non-final leg: as p, but next leg will have different range (leaper <-> rider).
y ('fork') in non-final leg: as g, but on an empty square. (FyafsF = Griffon)
j on sliding move makes the first step of the slide double the size, skipping one square. (jB = Ski-Bishop)
oo ('cylinder') moves wrap in toroidal fashion (left <-> right and top <-> bottom).
q ('circular') rider bends 45-degrees in same direction on every step. (qN = Rose)
i ('initial') as leading modifier: only virgin pieces have the described move. (KimN)
i ('iso') in continuation leg: slider leg has as many steps as a previous slider leg. (aivsQ = Sissa)
hr ('chiral'). new direction set: all oblique moves bending right of orthogonals. (hrN)
hl mirror image of hr. Do not confuse these with rh/lh, (right and left half
).
The diagram recognizes and asterisk * as a special range indicator,
indicating a position-dependent range,
namely the number of ranks between the current square and the enemy board half
(but at least 1).
A move with this range will always create e.p. rights on the squares it passes through.
Click here to open color legend
XBetza sandbox
Type a move definition below, and then click
Betza string:on the move above you want to replace.
To practice a bit with (X)Betza notation you can use this interactive diagram, which allows you to (re)define the moves for all piece in it, through the text entry below the piece table.
The diagram supports most of the Betza notation as discussed above; the modifiers n and j only work predictably on diagonal and orthogonal atoms, though. It also supports the XBetza extension (but not more than one locust capture per turn). The new atoms are:
Multi-leg moves (changing mode, range and/or direction between legs) are defined by joining groups of modifiers for the individual legs by a ('again') modifiers. (More about a...) New modifiers, or modifiers with a slightly different meaning on non-final legs:
The diagram recognizes and asterisk * as a special range indicator, indicating a position-dependent range, namely the number of ranks between the current square and the enemy board half (but at least 1). A move with this range will always create e.p. rights on the squares it passes through.