Comments by panther

I edited (added to) the first & last paragraphs of my previous post, in case anyone missed it.

H.G. wrote:

Note that it is EXTREMELY ANNOYING that when you are logged in, and type a long message, or make along edit to an existing message, the system can say when you submit it "you must be logged in,please try again", and then has deleted all your text when you return to the submission form.

It may be little consolation at the moment, but what I do, especially if I have been logged in for a long time (& worry that the system might somehow log me out before I hit 'Submit') is I often copy all of what I entered before I hit submit. That way if the system does tell me I need to be (freshly) logged in, after logging in again I can paste what I previously entered, after re-requesting to start a message or edit.

It all, unfortunately, tends to reinforce the slight, albeit perhaps somewhat irrational, phobia I have about using computers, in case of such wasted effort, or unforseen problems.

In looking up the latest poll results online (on wikipedia) for the US election, I noticed reference to margin of error, and also noticed that it was naturally bigger for smaller sample sizes. In the following link:

https://en.wikipedia.org/wiki/Margin_of_error

It can be seen that a sample size of just 96 has a margin of error of 10%, but a sample size of 384 has a margin of error of only 5%. It struck me that for a study of piece values using computers, it might be vital to have a considerably large sample size of games where identical engines play against each other in order to be rather confident of conclusions drawn in contesting the values of different pieces. Perhaps the minimum ought to be a sample size of 384 games. In concluding such a study, it might be noted how the margin of error might affect the estimate of a piece's value, if it is at all significant (e.g. "plus or minus 0.125 pawns" [however that might be calculated] possibly stated, after some calculations that are made for a piece's value based on win/loss percentages for that piece).

In his study finding that in chess a knight is exactly worth a bishop, I recall GM Larry Kaufman used a huge number of games (1,000,000+?) between skilled humans to draw his conclusion with a high degree of statistical confidence. This might have been a flawed study all the same; it seems from chess books that most human chess authorities agree that a knight is a little worse than a bishop on average. My own guess is that looking at human vs. human games wouldn't necessarily produce the same statistical result as an engine vs. identical engine study, with such a huge number of games also being played, and all starting with an opening-stage position setup where a single bishop is pitted against a single knight. That's, at the least, since different people value bishops & knights (and under what circumstances they can be exchanged equitably) slightly differently, which affects people's decisions, and in turn the possible results of all the individual games counted in a study, in a more chaotic way than with engines. That's not to mention all too human blunders or lesser mistakes, although these might tend to even out more than discrepencies caused by different players valuing minor pieces differently. I should note though that I own one 1998 middlegame book that is quite content to quote human vs. human database statistics that have results in favour of 2 bishops over 2 knights (or knight + bishop) a big majority of the time, under varying conditions of even material otherwise, much as Kaufman found.

P.S.: In digging back through old Comments, I see that H.G. (if no one else) has in a way basically taken into account much (if not all) of what I posted above, and made computer studies with a minimum of 1,000 games, in at least some cases, e.g. Amazon vs. Q + N (don't know about sample size in the case of B vs. N), when calculating piece values via piece vs. piece(s) battles. Assuming the engine + methodology used is a strong one, I still can't square some of the results of computer studies with my intuition, to my bewilderment. A personal anecdote that's possibly amusing: at one stage when musing about margin of error in regard to piece value estimates, I thought for a second that if a knight (as a piece of lower or equal value to a bishop) were set to 3.0 and the margin were 10% then the margin of error for a study (of 96 games) comparing it to a bishop might be 3.0 x .1 = 0.3 pawns. In similar fashion, I thought if an archbishop were set to 8.0 with a margin of 10% then the margin of error for a study (of 96 games) comparing it to a queen might be 8.0 x .1 = 0.8 pawns. I soon saw no justification for tying margin of error to the assigned numerical value of a piece, and realized it must be incorrect math. :)

Another way to try to convert margin of error from a raw percentage into a percentage of a pawn could first involve considering what constitutes the numerical value of a minimum decisive advantage (i.e. an engine should win 100% of all games in a study with this much advantage). In chess, that's about 1.333 of a pawn according to the old book Point Count Chess; if we accept that value (for the sake of argument) then a margin of error of 10% (i.e. for a study with 96 games) could be converted to 1.333 x .1 = plus or minus 0.133 pawns worth of margin of error. This may be just more incorrect math, but oddly enough I don't see how to easily refute it at the moment, at least with my feeble/rusty math skills.

In spite of the light-hearted appearance of Smess, the use of pointers on cells to determine directions that a piece can move was an interesting feature introduced to the chess variants world by this game.

After playing over a handful of games, I'd tentatively value a Ninny piece as 1 and a Numskull as 2, with a Brain having the fighting value of a Ninny (though the loss of a Brain means the loss of the game).

I've played a few games of this variant with friends. I found that certain standard opening moves in chess were less attractive to me, such as any involving an early fianchetto (P-N3 intending B-N2) or Open Sicilians (1.P-K4 P-QB4 2.N-KB3 intending 3.P-Q4) with White, in both cases if the opponent still has a Hawk and/or Elephant to drop when still developing. However, play may soon get richer after the Hawks & Elephants are dropped, regardless. Also, unlike some variants with R+N compound pieces, there may be less likelihood such pieces will be similarily developed to cells on the same file, & then exchanged, right away in the opening. I don't quite like that if all Hawks & Elephants are captured then the game becomes indistinguishable from chess from that point on, but that doesn't affect my opinion that Seirawan chess should get a high CVP Rating. The extra pieces may make for a slightly crowded board near the beginning of a game, though that's even slightly more the case in my own Sac Chess variant (with no pieces to be dropped in it at all).

My estimates for the piece values would be: P=1; N=3.5; B=3.5; R=5.5; H=8; E=10; Q=10 and the fighting value of K=4 (though naturally it cannot be traded). Since I tend to believe a B is microscopically better than a N on average on an 8x8 chessboard, perhaps adjust N=3.49 (also adjust the H and E compounds minutely since they have a N component), though I also usually try to avoid listing ugly fractions for values.

For my own comparison of this fine variant to the equally fine McCooey's Hexagonal Chess, see my review for the latter variant.

Decades ago I saw values given for the pieces in Glinski's (that would seem to apply to McCooey's too): P=1; B=3; N=4; R=5; Q=9. I'd add that I estimate the fighting value of K=4 approximately (though naturally it cannot be traded).

This looks like a great game. A 10x10 board perhaps is as about as big a board one can hope to fit on a coffee table (e.g. as a decorative board), and still use fairly standard size chess pieces with.

I like all the possible (and exotic) endgames that can arise in this game. My chess friends and I that play this variant now & then are still at the stage of learning to avoid gross threats.

A valuation system given by H.T.Lau: R=9; CA=4.5; N=4; CO=2; M=2; P(after crosses river)=2; P(before crosses river)=1. Bear in mind that this is just for the context of this game, as naturally a rook would be of lower value in a chess-like game played with a board of these dimensions.

Once each side has a little development completed, Shogi games are action-packed as a rule.

A simplified valuation scheme, as given by Grimbergen (see Shogi wiki entry) is: P=1; L&N=3; S&G=5; B=8; R=9; PB=12; PR=13.

This submission may have more clearly spelled out some of the rules for Bombalot than I recall a Chess Federation of Canada magazine article did in the late 1970s. In spite of what to me seemed to be certain ambiguities in the rules back then, my non-chess playing brother loved playing Bombalot with me. One thing that the magazine article made clear was that if an Immobilizer is directly or indirectly pushed along by a tank, the immobilized pieces around it are pushed in the same direction, possibly resulting in a chain reaction of pieces on the same line(s), in the direction of the push (something similar goes if an immobilized piece is directly or indirectly pushed along by a tank). Another thing I recall about the magazine article was that the board was checkered as for chess, i.e. with a1 (with the White Imitator on it in the setup position) being a dark square, as in the Sir Bombalot link.

Note that some ambiguitie(s) to the rules may still remain, and should really be resolved before playing a game. E.g., if an opponent's Imitator moved last, what properties does your own Imitator now have? My best guess in this case would be it has the properties of the last non-Imitator piece of your own that you moved, assuming you didn't move your own Imitator last, too - in that case, the properties of one's Imitator may or may not be that of the opponent's last moved non-Imitator piece, depending on how far back one has to remember to recall the last non-Imitator move by either side(!).

However, this all goes against the part of the description of an Imitator, in this submission's version of the rules, that says: "...if the last move of the opponent was with an immobiliser, the player can move the imitator and freeze pieces of the opponent, which are frozen until the imitator moves again.". So, if we accept this submission's version of the rules as per the quotation, it seems to me to follow that an Imitator always has the properties of the last enemy non-Imitator piece that moved, until the Imitator is moved like (& then takes on properties of) another enemy non-Imitator piece that has subsequently moved, as odd an interpretation as that may seem.

Whether this version of the rules & my subsequent interpretation are correct or not, my next question regardless would be, if White is to move his Imitator at move one, how can it move & what properties does it have? One suggestion I can make is that White should not be allowed to move his Imitator at move one (except if removing it, through the allowed suicide-of-a-piece move rule), and it as yet has no properties. Another suggestion would be that at move one the White Imitator can move like any piece in Black's army (note that any such move would presumably be not so harmful for Black), but this idea somehow seems less natural; for one thing, White may need to declare what type of piece the Imitator is acting like, if Black wishes to move his Imitator at move one also.

Personally, I think that the part of the rules that states "The Imitator moves and takes in the same way as the last enemy piece that has moved." pretty much stands by itself (though note the 2nd paragraph of this Comment). I also think that the subsequent part of this submission's rules about the Imitator that I quoted earlier, re: the explanation of how the Imitator may act like an Immobilizer, seems wrong, in part. That is, the last 5 words at the very end of my earlier quote apparently ought to read '...until the Imitator is no longer adjacent or the opponent moves a piece other than his own Immobilizer (or possibly his own Imitator as well, depending on the situation).' instead, in my opinion.

For piece values I'd tentatively rate the Twekes = 1, Super-Twekes = 2, Detonators (aka Detonator Coordinators) = 1.5, Tank = 1, Immobilizer = 5, Bomb = 10 and Imitator = 5.

Crazyhouse (like Bughouse) is one of the most popular chess variants on the planet at the moment, and there has to be a reason. It's much like Shogi, but with chess pieces (and, unlike Bughouse, it's a 2 player game), making it especially popular with those who love bang-bang tactics (many or most chess players, I suppose).

{edit: below is an entry from a later post, for reference within this review:]

Fwiw, here are relative piece values for Crazyhouse that I once saw given on someone's blog:

P = 2; B = 3; N = 3.5; R = 4; Q = 6.

For comparison, and in case one might use it for Crazyhouse too, from the wiki entry on Bughouse: "A valuation system, first suggested by FICS-player Gnejs, often applied to bughouse is pawn=1, bishop=knight=rook=2 and queen=4."

The fact that one of the best chess players of all time (Alekhine) took the trouble to play at least one game of this variant may count for something.

In trying to tentatively estimate the value of the pieces in this variant, I'd guess that the long range pieces may be worth, say, one and a half times what I give them as in standard chess. Thus: P=1; N=3.49; B=5.25; R=8.25; Q=15 and the fighting value of K=4 (though naturally it cannot be traded).

Dice Chess is a light way to pass time with a chess variant when you don't feel like thinking too much.

Note that my estimates for the values of the chess pieces seems applicable here too: P=1; N=3.49; B=3.5; R=5.5; Q=10 and a fighting value of K=4.

As a variant that's close to chess, Fischer Random (aka Chess960) does the trick of avoiding all opening theory admirably.

One thing Chess960 lacks compared to chess is ironically usually seen as it's very strength and reason to exist, i.e. that one can't study Chess960 opening theory at home (if that's viewed as desirable/enjoyable), plus book sales thus will suffer, arguably to the detriment of popularizing the variant. This would be partly due to not otherwise having more literature around (i.e. about the opening phase of Chess960).

A way to solve that to some extent is to adopt Kasparov's idea of using the same starting position for a year & then switching to a new one. I'd go farther and suggest not switching the start position for 50 or even 100+ years (chess opening theory took a long time to develop, after all). One drawback of this idea is that the game would be studied to death by, say, 960x100 years from now, whereas never knowing the position one will begin with, as per the rules of Chess960, would avoid such study. However, the lifespan of any board game of skill (e.g. chess) is liable to be finite for one reason or another, IMO.

My estimates for the values of chess pieces applies here too, naturally: P=1; N=3.49; B=3.5; R=5.5; Q=10 and a fighting value of K=4 (though naturally it cannot be traded).

I've edited (added to) my previous comment, for any who missed it.

Here's a link that includes discussion of the rating equivalent of pawn or knight odds for a game of chess:

https://en.wikipedia.org/wiki/Chess_handicap#Rating_equivalent

The idea that rating relates so strongly to the ability for a human to normally convert a material advantage of a given magnitude (e.g. pawn) from a given starting position in chess made me wonder if the same applies to engines that aren't particularly strong, whether they're playing against a human or another engine.

Like Bombalot, Arimaa is a variant that's very unlike chess, in that there are no matable kings, but it can make use of standard chess equipment. Arimaa might have spread over-the-board better were it not for the licensing requirements for e.g. literature or running tournaments. It's perhaps too bad world championship level human Arimaa players finally lost in a challenge series vs. a bot (engine) in 2015.

Bughouse is an excellent 4 player variant that can be played with a different number of players, or (as a Bughouse variant) even a greater number of boards & sets than just two, if desired. Fwiw, I've seen on internet chat sites talk that Bughouse is hard for engines, as there are two boards & sets + drops, multiplying the possibilites compared to standard chess. If ever one of the two boards has a player sitting (refusing to move), however, the computer may then have an advantage if playing against a human on the remaining board (provided that person doesn't already have a big advantage).

From the wiki entry on Bughouse: "A valuation system, first suggested by FICS-player Gnejs, often applied to bughouse is pawn=1, bishop=knight=rook=2 and queen=4."

I've seen on an internet chess chat site a Canadian Candidate Master claim that (in at least one of the three main variants of Progressive Chess, if not all), Black has a slight advantage, if playing 1...d6 + 2...Nf6 against most White first moves,

In trying to tentatively estimate the value of the pieces in Progressive Chess (in its main variants), I'd guess that the long range pieces may be generally worth, say, one and a half times what I give them as in standard chess. Thus: P=1; N=3.49; B=5.25; R=8.25; Q=15 and the fighting value of K=4 (though naturally it cannot be traded).

Perhaps this game is best suited for a speed chess time control, as a previous poster alluded to in a way.

In trying to tentatively estimate the value of the pieces in this variant, I'd guess that the long range pieces may be worth, say, double what I give them as in standard chess. Thus: P=1; N=3.49; B=7; R=11; Q=20 and the fighting value of K=4 (though naturally it cannot be traded).

Fergus wrote on 2016-09-13: None

...Chess has been finely honed by natural selection to be free of arbitrariness. Every rule and piece in Chess serves a purpose, and none are arbitrary. Since Chess is what won the survival of the fittest among Chess variants, I expect that any variant capable of succeeding Chess would also have to be free of arbitrariness. But most Chess variants differ from Chess through some arbitrary change to it, and they easily get lost in a sea of variants that each differ from Chess in their own arbitrary ways...

In a way I like seeing this opinion, as a chess player (who also has fully recovered from some loss of faith in chess due to computers). However, I'm fairly sure you didn't mean to say that chess has so far been clearly superior in terms of merit to all chess variants. That would be a little disconcerting, even to me (after my venturing into the world of variants), since I concluded that among the dozens of variants I looked at (however briefly), many even in my eyes had compensating merits for anything they might lack compared to chess - some are quite different to chess and are hard to fairly compare. What e.g. Circular Chess lacks in terms of basic mates compared to chess, it makes up for in certain other ways (though initially these ways did not impress me so much), and Circular Chess may well not even be one of the better variants objectively (if objectivity is possible comparing variants).

I'd also wonder a little about whether chess doesn't have any arbitrary aspects to it, too (some might say any game or sport must have some arbitrary rules/kludges). For example, stalemate being a draw could be ruled as a win (or 3/4 of a point) for one side, instead (but that would spoil many fine stalemating combinations/swindles, besides altering current endgame theory). One thing 8x8 chess has going for it is that bishops are very close to knights in value (even for those who quibble), so variants on other board sizes and/or shapes may lack this nice feature. However, in Glinski's Hexagonal Chess, for example, where apparently a knight is worth a pawn more than a bishop, interesting trades of knight for bishop and pawn can frequently occur (I think), rather than bishop for knight as in chess, making the nice equivalence of a B for N in chess something that's not so meaningfully special.

I think what has made chess so popular is that given its rules & 8x8 terrian, it works remarkably well (e.g. in producing many brilliant games between people), and no one seems to know exactly why. Still, remember that Shogi & Chinese Chess are considered "Classic" variants, too.