Ratings & Comments

I now fixed the Play-Test Applet's GAME-code generation such that it does use the correct way for specifying a move as imitation in the 'legdefs' table it generates.

One caveat: the trick the betza.txt include file uses for determining whether moves are legal during highlighting is not reliable when imitators are present. Because it determines the pinned pieces and attacked squares before the move. And the move will usually change what the imitator is immitating. So it is recommended to use highlighting of all pseudo-legal moves, by specifying

set pseudo 1;

at the end of the Pre-Game section.

Thanks, for that HG!

It seems in the game code I can castle out of check and that should not happen.

I think it just highlights the move as legal but doesn't let you actually do it.

I verified this. You are correct!

That is a consequence of pseudo-legal highlighting. The issue of moving into / out of / through check is what makes the difference between fully legal and pseudo-legal moves.

Ok!

@HG, Hello I want to use the dummy piece trick here the way you suggested a while ago. I don't know how to define the dummy pawn (a pawn with no capture, en passant or promotion).

EDIT: I mean without having to redo the diagram from scratch.

Can you help me?

I think another design contest would be nice. I like having the option of two different numbers; I could do something nice with 62 spaces if we need more submissions.

(This is the same Sam Trenholme who made Schoolbook a long time ago. I’ve given up on password recovery, so I’m just using a new account. As an aside, Gmail isn’t getting the verification emails.)

Whether a piece can promote or not depends on its ranking in the piece list and the value of maxPromote. If you want a Pawn that cannot e.p. capture you just leave out the e mode. E.g. fmWfcF instead of fmWfceF.

You will find it in the alphabetical index under P. It can generate GAME code for rule enforcement / highlighting in Game Courier presets. But it has no provisions for uncommon rules like Frog kissing, or mixture of chess and shogi promotions. So it would be necessary to supplement it with code of your own.

To add a new piece (say X / x)  to the GAME-code generated by the Play-Test applet you would have to add its move definitions at the end of the legdefs array, and supply functions X and x that return where in the legdefs array you have done that. Determining the latter is a bit of a pain; there are comments in the legdefs table that in parentheses indicate where the definition for each piece type starts, and you can then count the numbers appearing after that. Note that because the 'bare Pawn' is an asymmetric piece you would need different definitions for the white and the black one.

The move definition of a (white) FIDE Pawn is:

1  1  0  1     1
1  1  1  1     2
1  1 -1  1     2
1  1  0  2   16577 // pawn(1)
1  1  1  1     4
1  1 -1  1     4
0

The first 3 lines would suffice for the Shatranj Pawn; each line starts with the number of legs (always 1 here, as Pawns only have simple moves), the forward and sideway step size, the 'range' (= number of times the step can be repeated) and finally a code to indicate what the move can do (2 = capture, 1 = non-capture, e.p. capture = 4) and other details (like whether it is a virgin-only move). So the 4th line is the double-push, the 5th and 6th are the e.p. captures. For your bare Pawn you would leave these lines out. The final 0 indicates that the definition ends there, and that the moves that follow (if any) are for another piece. The move specifications for a piece should always end with such a 0.

In the example I copied this from the white Pawn was the first piece, so it starts at element 1 of legdefs. The special moves of that Pawn start at element 16 (as the three normal moves each take 5 numbers to describe). That means that just behind legdefs there is a line

def P cond #0 1 16;

that tells the code that the move definitions of piece P start at 1 (normal moves) and 16 (special moves = moves having side effect, such as creation of e.p. rights, or disappearance of pieces elsewhere). For pieces without special moves the latter number should always be 0. So for the bare Pawn you would have to add a line there like

def X cond #0 ... 0;

where the ... is the location in legdefs where the move definition starts.

@HG, I had managed to do it despite some small setbacks. You know what's funny? This game also has berolina pawns!

I have also created dummy berolina pawns and made the trick for them, too!

In my opinion riders based on a leap other than a king step are very awkward to play with. That holds for NN, but also DD and AA. It is never intuitively clear whether the path between such a rider and a distant target is blocked, especially when the blocker is far from both. For me that makes them annoying pieces.

I guess the problems with tactically non-quiet opening positions can be avoided by putting all pieces more valuable than a Nightrider two ranks behind the Pawns. Then the Pawns will block any Nightrider attacks on them. And of course make sure all Pawns and pieces directly behind them start protected.

I find nightriders difficult to visualize, even with the three-colored board, but despite that they seem to work well in the grand apothecary games since there are enough pawns and weaker pieces to block them.