Spartan Chess

How do you determine the values of the pieces? I always have difficulty deciding whether to exchange the FIDE B/N with the Lieutenant/Captain when playing the computer. 

And can you point me to the End-Game Tables? Try googling it without success.

I always determine the piece values by play-testing from initial positions with unbalanced material. Just give one player two Captains instead of Knights in the FIDE setup, and let the computer play a couple of hundred games, and look which player scores better (and by how much). From tests like that I obtained

second Bishop > Lieutenant > first Bishop ~ Knight > Captain.

Although the differences are not very large. Warlord plus Pawn is slightly better than Queen, and the spare King is better than any minor, but worse than a Rook. The General is about halfway between Rook and Queen. Persian and Hoplit Pawns are about equal in value (but depends a lot on the Pawn constellation).

I must have published the EGT results on some forum (probably TalkChess); some are here: https://www.chessvariants.com/index/listcomments.php?order=DESC&itemid=MSspartan-chess . Redoing them would probably be faster than trying to look it up; I use FairyGen to calculate the 5-men end-games. (It can only do 8x8 boards, but that happens to be OK for Spartan Chess.) For 3-vs-1 (or 2-vs-1) EGT yu can try the Checkmating Applets at chessvariants.com.

I recalculated a few Spartan end-games: Because the Captain has mating potential, end-games of 2 light pieces vs 1 are generally won when the strong side has a Captain (KCCKN, KCCKB, KCLKN, KCLKB). If the weak side has a Rook, not even two Captains can win. I actually used a 'Modern Elephant' for calculating this, i.e. without the sideway step, but if that already wins, the Lieutenant certainly will. (And calculations with a true Lieutenant are slower, because of the reduced symmetry.) KLLKN is a forced win, (this really needed Lieutenants), but like KBBKN takes on average more than 50 moves, so almost always is a draw in practice. No pair of Persian minors can beat Captain or Lieutenenant.

Wow, thanks for your detailed analysis and recommended link. You have provided good insights on how Persian army should engage the Spartan army (eg. Avoid R exchange with Spartan K) and the value of the pieces as endgame approaches (eg. Exchange Persian Minor with Spartan Minor) generally. In my humble opinion, the beauty of the game lies in how each army coordinate its pieces with its Pawn constellation.

I forgot to post any of the 4-men results. Rook vs Captain or Lieutenant is a draw, as might be expected. (Checkmating with a Rook is only possible through zugzwang, which you cannot exert if the opponent still has another piece. And the Spartan light pieces are even more difficult to catch than a King.) A General vs Rook or Bishop is generally won, though. (It doesn't need the zugzwang, as it can mate or drive the King back in a contact check though its King move.) The even stronger Warlock also beats a single FIDE minor. Likewise, Queen vs Captain or Lieutenant is a win too. The strength difference is just too large.

I cannot really generate EGT with an extra King according to the Spartan rules (extinction royalty, but duple-check). I can do a royal plus a non-royal King, though, which is a slightly weaker combination, because loss of one of the Kings (the royal one) can count as a loss there, while with extinction royalty it never would. Even a non-royal King is a 'strong defender', though: KQKK is a draw when the Kings can be connected (where KQKR would be a win). The point is that the King cannot be approached by another King, so it can never be attacked twice. But in 3-vs-2 end-games, where the strong side has a piece it can afford to sac, it is a different matter: KRBKK and KRNKK are both general wins. It is not certain this would also be true with Spartan rules.

Very intriguing

HG have you heard of Stargate? It has 7 gateable pieces on a 10x10 board with freeform castling and a lot of unique pieces. One "teleports" the enemy to their own back row, except the king, which can be teleported anywhere, even into checkmate. One is a piece freezer and that piece not only can't move, that square becomes off the board and sliders cannot slide past it. There is a Neutron Star that distorts gravity, and places like a Star Trek force field in front of it that the enemy cannot pass. Another piece can heal a frozen piece and return it to play. It's complicated, more like an army strategy game.

I have seen it in the Gothic Chess thread, IIRC. No reason to repost it in every thread that is about a specific other variant...

I was told that it is impossible to program because it has pieces that do not capture. I heard you wrote a program that can play any variant. I was curious to know if you believe it cannot be programmed either.

'Any variant' is an exaggeration. My engine Fairy-Max has adjustable (but rectangular) board size up to 14x16, and can handle pieces with a large variety of moves (any slider, leaper or hopper, or their compounds, (singly) bent sliders, lame leapers). That is enouh to support an enormous number of variants, but it still leaves a lot of things it cannot do. Amongst those are piece drops, multiple captures, hit-and-run captures... And pieces with side effects (e.g. immobilizers, pacifiers, coordinators, transparency inducers, catapult or magnetic pieces). It seems Star Gate is full of the latter. With so many weird rules that no other variant would ever use, it only makes sense to make a dedicated program for it.

First International Online Spartan Chess Tournament March 27th 2021

Follow this link for tournament details

Play Spartan Chess online here: vchess.club

You can see the rules in detail here: Spartan Chess Description and Rules

blessed

You can now play correspondence games at the Ludii Portal.

https://ludii.games/details.php?keyword=Spartan%20Chess

If one of the two can move to safety: nothing. The opponent can then capture the other. (But might not want to do that, when it is protected and the attacker was Rook or Queen.)

You must have one King that is not under attack at the end of your turn, though. If you cannot achieve that, you are checkmated even with two Kings present ('duple mate').

Download STL file Chess, Arabic and Roman chess pieces • 3D print object ・ Cults (cults3d.com)

looks like perfect for Spartan Chess. please go check it out