opposite castling armageddon

[lkaufman]

I have wondered what would be the simplest rule change to chess that would make it a two-result game (win or loss) while still being roughly fair to both players. In the real chess world this is sometimes done by giving White more time and Black draw odds, but with a few exceptions this has been done only at ten minute or faster time limits. Let's say we won't use time in the rules, equal time is assumed. Here is what I think might be an original, simple, and fair enough solution.
White is not allowed to castle long, Black is not allowed to castle short, Black wins draws. That's it. It is a subset of normal chess; if you stipulate the starting sequence 1.Na3 Nh6 2.Rb1 Rg8 3.Ra1 Rh8 4.Nb1 Ng8 you get the above castling status. Since castling short is easier to accomplish than castling long and doesn't require an extra move to "finish" the castle (Kb8) White's advantage is obviously larger than normal, despite the symmetry of the rule, and the fact that same side castling never happens makes the draw odds less significant. But it's far from clear which side has the better chances or the theoretically won position. Most people would rather play White, because it's more "fun", but whether White would score more than 50% in either human vs human or engine vs engine play is not obvious. Recent strong versions of Lc0 give White about 68-70% win exp. with draws counting as a half, which is close to the point where White would win half the games outright. Stockfish and Komodo give White a bit more of an advantage than what I would normally call the line between a draw and a win (about .7 for Komodo, about 1 for SF). I had ten different Lc0 networks play it out using the "Shootout" feature on Fritz, at 2' + 1" on rtx 2080, and White won four, drew six. My hunch is that White will come out slightly ahead in human GM play, perhaps about even or a bit behind in engine play, but of course it's very hard to predict, and ten games with similar engines means little.
So who would you bet on, White or Black. First case top human GMs playing, second case top engines. And who benefits from longer time controls, White or Black? Is it roughly fair? It doesn't have to be perfectly fair, as players alternate colors and chess isn't at all fair in that sense now.

[Ovyron]

For playing, I'd pick black. Back when I adopted a quiet strategy for chess I was able to hold the black pieces against players 400 elo stronger than me, and I just abandoned it because it got boring, but if I'd have gotten wins instead it'd been fine, but if my opponents would have gotten a loss in those cases, they'd have played very differently and showed their superiority, which sounds more exciting than what we got.

With white it doesn't happen, against 400 elo stronger opposition, there's no way in hell I'll beat them, they just need to hold the draw and get a win, any attempt would just backfire and they'd beat me instead. The same concept remains for weaker opponents, once you're strong enough to hold the draw you'd just not bother to win, so black becomes the most appealing color.

So this concept would only be optimal with equally rated opponents, but as the rating difference increases the black side becomes more appealing.

What is interesting is how would engines be programmed to play this variant, as a 0.00 score is losing for the white side, normal approaches wouldn't work.

Another idea is to have a chess variant where one side tries to get decisive result (checkmate or get checkmated) while the other tries to end game in draw, though maybe it doesn't make a difference as if you have enough advantage to make opponent checkmate you, it'd be faster to just checkmate them.

[JohnWoe]

Why not KOTH (King Of The Hill) as it is basically a 2 result game? There is no endgame as kings can reach (d4, e4, d5, e5) squares all the time. Unless the center is blocked. Then it is a draw. But that is very rare. I think for armageddon games KOTH makes a lot of sense. As it is symmetrical setup. Plus times are equal.

I see this fen still very much drawish:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w Kq - 8 5

[Laskos]

I see this fen still very much drawish:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w Kq - 8 5

Not only it is fairly drawish at tournament TC and strong players, but giving Black the draw odds, the expected score of of White vs Black between 2 equal players is not stable with TC (or strength), the score increasing for Black with larger TC.

[OneTrickPony]

What about: white gets to make 2 first moves and gives draw odds.
Lc0 eval is similar to opposite castling armageddon proposed in OP but it's even simpler to explain.

[Look]

Hi,

What if both sides play two extra blitz games , until someone is a winner in double games ? No such single game armageddon as you may expect.

[lkaufman]

I see this fen still very much drawish:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w Kq - 8 5

Not only it is fairly drawish at tournament TC and strong players, but giving Black the draw odds, the expected score of of White vs Black between 2 equal players is not stable with TC (or strength), the score increasing for Black with larger TC.

I'm not disagreeing with you, but do you have data that suggests it is drawish? The Komodo and SF evals are clearly in what we would call the winning zone. Lc0 perhaps a bit on the drawing side. As a human gm I would be inclined to choose the White side if I wanted my best chances; it's quite difficult for Black to castle queenside in many openings without making serious concessions. One way to modify it to increase White's edge a bit is to allow White to castle either side, only limit Black to queenside only. But I felt that it was already too favorable for White without this change.

[lkaufman]

What about: white gets to make 2 first moves and gives draw odds.
Lc0 eval is similar to opposite castling armageddon proposed in OP but it's even simpler to explain.

Of course I considered that too. I think that the castling rule is more favorable for White than the two move rule, and that the two move rule is not quite enough to give White equal chances with Black getting the draw odds. But I could be wrong. Also, the castling rule feels more like normal chess; you can still play queen's gambits, sicilians, spanish, French, etc., although their relative merits will be different from normal chess.

[Guenther]

What about: white gets to make 2 first moves and gives draw odds.
Lc0 eval is similar to opposite castling armageddon proposed in OP but it's even simpler to explain.

I did a quick test with CFish20190717 vs. itself and surprisingly the draw rate was still very high > 70% at a fast tc of 40/40''.
used this set of positions:

Code: Select all

rnbqkbnr/pppppppp/8/8/3PP3/8/PPP2PPP/RNBQKBNR b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/3P4/5N2/PPP1PPPP/RNBQKB1R b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/2PP4/8/PP2PPPP/RNBQKBNR b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/2P5/2N5/PP1PPPPP/R1BQKBNR b KQkq - 0 1
kbnr/pppppppp/8/8/2P5/6P1/PP1PPP1P/RNBQKBNR b KQkq - 0 1
kbnr/pppppppp/8/8/2P5/5N2/PP1PPPPP/RNBQKB1R b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/4PP2/8/PPPP2PP/RNBQKBNR b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/4P3/2N5/PPPP1PPP/R1BQKBNR b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/8/1P6/PBPPPPPP/RN1QKBNR b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/8/6P1/PPPPPPBP/RNBQK1NR b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/5P2/5N2/PPPPP1PP/RNBQKB1R b KQkq - 0 1
rnbqkbnr/pppppppp/8/8/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq - 0 1

[Nordlandia]

For balance is it better let black castle kingside or queenside. Queenside castling is generally considering more aggressive than kingside castling.

Considering white moves first maybe it's good idea to let black castle queenside. Somehow offsetting the first move.

Now the real tough question is whether if tempo such as Kb8 from c8 is more important than Re1 from f1. Is moving the king out of the c8-h3 diagional
on average more of an wasted tempo than than the development Rf1-Re1 ?

Queenside castling suffers from the exposed diagonal but it's very nice to get the rook centralized. But i think kingsafety prevails on average.