asean chess engines and rating list

[Ferdy]

Introduction at home page:

Code: Select all

It is a variant that are suited for strategic players. It has no powerful piece that moves like a queen in chess, and it has no piece that moves like a bishop in chess. The only strongest piece is a rook. This variant also suits players who like to play endings. This is probably the variant where a human can play toe to toe against an engine.
The major difference from chess is that the queen in this variant would move like a bishop but within 1 square only. And the bishop in this variant would move like a bishop but within 1 square only plus 1 move forward, this piece is like a silver general from shogi. See also the rules in game rules menu.
There are only 3 engines that I know that can play this variant namely, Silangan by Me, Sjaak by Evert and Fairy-Max by H.G.Muller, see also the engines menu.

https://sites.google.com/view/aseanchess/home

Rating list.
https://sites.google.com/view/aseanchess/rating/blitz

Game rules.
https://sites.google.com/view/aseanchess/game-rules

For chess programmers this is very easy to create as this is played in 8x8 board and just change the queen and bishop movements which is also easy to create.

Revised piece movements.

[hgm]

Note that this is a variant of Makruk (Thai Chess) that apart from giving the pieces other names, differs only from Makruk by the size of the promotion zone, (1 instead of 3 ranks) and the fact that there is promotion choice (rather than promotion to the next-to-useless 'Queen' only),and the symmetry of the start position (flipped instead of rotated). And perhaps the counting rules are a bit different, I never really studied those.

The promotion choice has a large impact on the game. Makruk is very drawish, because promotions hardly gain you anything, so that an advantage of a Pawn is not decisive. (You need about 3 Pawns, and even then you might be unlucky if they all promote on the same color In ASEAN you can promote to Rook, which usually is decisive.

The counting rules (a kind of material-dependent 50-move rule) seem to have only little impact on the game, as you can easily avoid their invocation by refraining from capturing the opponent's last Pawn. WinBoard does not enforce these rules, although it would probably not be very difficult to do so.

[Ferdy]

The counting rules (a kind of material-dependent 50-move rule) seem to have only little impact on the game, as you can easily avoid their invocation by refraining from capturing the opponent's last Pawn. WinBoard does not enforce these rules, although it would probably not be very difficult to do so.

It is not really an opp last pawn but an opp last piece except king.
This specific rule is intended for humans delaying the won game and opp not resigning. In bullet or blitz this is totally a different story. For engines, the programmer has to make an effort to mate the opponent as quick as possible or within that limit.

Code: Select all

Lone King vs. King & A Rook 16 moves

This rule would force humans to study kr vs k ending religiously

[hgm]

Indeed, the number of moves you get is pretty tight. In fact it can be impossibly tight: the number of pieces present is subtracted from the allowed moves. So if you are ahead too much, you can be left with zero or less moves ('auto-draw').

These rules can make end-games where you are very much ahead a real contest. The downside is that it does this by turning won end-games into draws, making the game even more drawish than it already is due to the large numberof end-games that are dead draws.

And, like I said, if you really are very much ahead, there doesn't seem to be any need to bare your opponent. This is the solution I would use in an engine. Just divide all scores where there is a bare King by two, like you would do for pawnless endings in Chess. I expect that this poor-man's solution would solve the problem in >90% of the cases that you encounter in practice, without going into the details of the counting.

[Evert]

I have a private Makruk engine that is planned to also play ASEAN. At the moment it doesn't though.
How well it would play is also debatable, of course, because things like passed pawn evaluation are very different between Makruk and ASEAN.

I can have a look at making it play ASEAN over spring break.

[Ferdy]

I have a private Makruk engine that is planned to also play ASEAN. At the moment it doesn't though.
How well it would play is also debatable, of course, because things like passed pawn evaluation are very different between Makruk and ASEAN.

I can have a look at making it play ASEAN over spring break.

I prefer asean over makruk. Asean has a simplified counting rules, and you can promote to other piece type which is fixed in makruk.

I am testing nebiyualien as it can play this game by defining a variant on its ini file.

Perhaps 3 months from now i will organize a championships.

[hgm]

Btw, it seems the rules page that you give the link to contains some nonsense, which makes me doubt whether these are official rules: it says you have a 64 moves before KNQK is a draw. But KNQK is always a draw, similar to KNNK. KNQQK is a win, both with like and unlike Q.

It is also not clear whether the mentioned pieces shouldbe the only ones. E.g. in KRPK, do I still get 16 moves, or an infinite number because I have the extra Pawn? Getting more moves when you are more ahead makes no sense. Even if you always get 16 move in KR...K, it seems unreasonable that you also get 16 in KRRK. And in KNQ...K you obviously should not have any R amongst the additional pieces.

At least in Makruk the counting rules are well defined:

Code: Select all

    If there are two rooks left: 8 moves
    If there is one rook left: 16 moves
    If there are no rooks left, but there are two bishops: 22 moves
    If there are no rooks left, but there is one bishop: 44 moves
    If there are no rooks or bishops left, but there are two knights: 32 moves
    If there are no rooks or bishops left, but there is one knight: 64 moves
    If there are no rooks, bishops, or knights, but queens: 64 moves

All with possibly extra material. And the allowed moves are always reduced by the number of pieces present.

[Evert]

Btw, it seems the rules page that you give the link to contains some nonsense, which makes me doubt whether these are official rules:

It seems so. The rules at http://aseanchess.org/laws-of-asean-chess/ appear to be the same.

it says you have a 64 moves before KNQK is a draw. But KNQK is always a draw, similar to KNNK.

It isn't exactly the same as KNNK.
[d]8/8/8/3B4/3Q4/4K3/8/3k4 w 0 1
is (apparently) mate in 29:

Code: Select all

#([Makruk] 0w)>setboard 8/8/8/3S4/3M4/4K3/8/3k4 w 0 1
 8                
 7                
 6                
 5      S         
 4      M         
 3        K       
 2                
 1      k         *
  a b c d e f g h 
#([Makruk] 0w)>go
# Generate tablebase for KMSK
#  1:    2874   45.68ms
#  2:    2672    3.75ms
#  3:    2170    4.50ms
#  4:    6952    5.10ms
#  5:    5126    4.59ms
#  6:   10154    4.11ms
#  7:   16546    4.77ms
#  8:   23362    5.41ms
#  9:   33578    8.98ms
# 10:   41386    8.24ms
# 11:   50466    8.10ms
# 12:   56714    9.35ms
# 13:   64418    9.00ms
# 14:   73868   12.08ms
# 15:   94668   17.80ms
# 16:  115398   14.42ms
# 17:  137780   16.00ms
# 18:  159320   18.84ms
# 19:  173832   23.63ms
# 20:  187364   20.28ms
# 21:  208042   22.20ms
# 22:  216872   28.67ms
# 23:  235094   22.58ms
# 24:  247788   29.20ms
# 25:  268896   25.80ms
# 26:  275176   25.90ms
# 27:  293304   29.34ms
# 28:  314390   26.80ms
# 29:  335474   32.07ms
# TB: Mate in 29 (57 ply)
  1  15943      1        49    1. Kf2   Kd2   2. Sc4   Kd1   3. Sd3   Kd2   4. Se2   Kc1   5. Se3   Kb1   6. Sd2   Ka1   7. Mc3   Kb1   8. Ke1   Ka2   9. Ke2   Ka3   10. Kd3   Ka4   11. Kc4   Ka5   12. Md4   Kb6   13. Kd5   Kc7   14. Me5   Kb6   15. Sc3   Kb7   16. Kd6   Kc8   17. Ke7   Kc7   18. Sb4   Kc6   19. Ke6   Kc7   20. Sb5   Kd8   21. Sc6   Kc8   22. Md6   Kb8   23. Kd7   Ka7   24. Sb5   Kb7   25. Mc5   Ka7   26. Kc6   Ka8   27. Sa6   Kb8   28. Sb7   Ka7   29. Mb6   
move Kf2

It is also not clear whether the mentioned pieces shouldbe the only ones. E.g. in KRPK, do I still get 16 moves, or an infinite number because I have the extra Pawn? Getting more moves when you are more ahead makes no sense. Even if you always get 16 move in KR...K, it seems unreasonable that you also get 16 in KRRK. And in KNQ...K you obviously should not have any R amongst the additional pieces.

This is indeed not obvious, but I think the intention is that you get 16 moves for all KRxK, where x is any set of pieces.
It might be good to verify this against the non-English rules though (assuming those are not ambiguous).

[hgm]

Your example is KBQK. Not KNQK. From the Makruk rules you can see that R > B > N > Q as faras matiing abilities go.

The problem is that if 'x' is any set of pieces, how many moves would KRBNQK get? It is KNQxK with x=RB. So should it get 64 moves? It would require definition of an order relation between the pieces, and the addition "any set of LOWER (or equal) pieces". But no such order relation is defined. And it is strange that no move limit is given for KBNK, which should be winnable.

It seems that a few end-games are singled out in a totally arbitrary way.

[Ferdy]

Btw, it seems the rules page that you give the link to contains some nonsense, which makes me doubt whether these are official rules: it says you have a 64 moves before KNQK is a draw. But KNQK is always a draw

You are wrong here, see this.




The rule mentions of a word particular.

e. As soon as a player has only a king left on his side, the number of pieces belong to the opponent shall be observed. The game may be drawn if the player having only a king (lone king) left on his side can manage to escape in a number of fixed moves (move count shall be done starting from the very first move of lonely king) against the opponent of having particular pieces shown below:
Lone King vs. King & A Rook 16 moves
Lone King vs. King & A Bishop & A Queen 44 moves
Lone King vs. King & A Knight & A Queen 64 moves

Examples:
KRR-K, no counting
KRP-K, no counting
KR-K, use counting

That is how I understand that special rule.