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Comments by Thomas McElmurry

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Thomas McElmurry wrote on 2010-06-12 UTC
Whenever someone announces a system for beating the house, one should check
carefully before believing it.  If my computation is correct, the proposed
algorithm leads to an expected loss of about $41.57.

For those few individuals with a sufficiently large bankroll to survive
the possible large loss, this game might be mostly harmless, and perhaps
it's an amusing way to blow 42 bucks.  But I wouldn't recommend it as an
investment strategy.

Game Courier Tournament #4: An Introductory Semi-Potluck. A tournament to feature games good for introducing people to Chess variants.[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2010-05-06 UTC
If there is an injured party, I don't think it's me.  I was surprised by the repeat pairing but didn't realize it was a mistake.

Despite my 0-2 score, I didn't feel hopelessly overmatched in those two games.  In the first game I may have been winning, but underestimated the importance of king safety against a rampant marshal.  In the second game I had an extra pawn and a decent position until I blundered a major piece.  Even if the pairings had been different, I could have blundered against any opponent.

I don't think any correction is needed as far as I'm concerned.

3D Great Shatranj. A simple approach to 3D chess. (6x6x6, Cells: 216) [All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2010-04-09 UTC
It's not a cheat; it's just the way this Elephant moves.  There's no law saying every piece's moves have to have the full symmetry of the board.

In fact this Elephant is very interesting, because the Elephant is colorbound on one coloring of the board, while the Knight is colorchanging on another coloring.  It should be fun to watch them interact.  (Reminds me a bit of Alice Chess, where the Bishop and Knight are both colorbound, but on different colorings.)

Game Courier Tournament #4: An Introductory Semi-Potluck. A tournament to feature games good for introducing people to Chess variants.[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2010-03-22 UTC
Yes, that's what happened.  I had gone back one move to look at the previous position, and then I think I just went back in my browser history, so that I was looking at the current position on screen, but the server was working with the previous position.  Usually I'm careful to avoid such things, but this time I forgot (I must have been distracted by my increasingly uncomfortable position).

I hadn't meant to take back a move, and I've replayed my previous move so that we can restore the correct game history.

Thomas McElmurry wrote on 2010-02-20 UTC
I was thinking of requesting the same thing before the next round of Circular Chess games. The JPEG compression artifacts can be rather distracting. In some cases one can get rid of them, e.g. by specifying quality=100 in the URL, but I couldn't find a way to make this work with my userid specified (e.g. when entering a move).

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Thomas McElmurry wrote on 2010-02-10 UTC
And they're playing on a large board.

Game Courier Tournament #4: An Introductory Semi-Potluck. A tournament to feature games good for introducing people to Chess variants.[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2010-01-02 UTC
It seems to be working now. After my last move in Euchess, Jose has 15+ days of reserve time.

Thomas McElmurry wrote on 2010-01-02 UTC
Ten is not just an even number. With 18 games per player, ten players are just right for a double round robin.

I always like to have a link to all the games in the tournament.

Is the bonus time working properly? My opponents and I have exchanged several moves within the 12-hour grace period, and I don't think any of us have received the six-hour bonus.

Oh, and Happy Palindrome Day to one and all!

Thomas McElmurry wrote on 2009-12-21 UTC
I'd like to sign up, provided the time controls are such that I can safely average 1 to 1.5 moves per game per day.  If I had been in time to suggest a game, I probably would have suggested Extinction Chess.  But the six selections look like a good set of games.

Just in case it's being seriously considered, I'll say that I'm not a fan of Sam Trenholme's proposal for adjudication of long games.  If the point of the tournament for most of us is to try out new games, it would be a shame to be deprived of an interesting endgame.

How to Generate OTB Random Positions. How to generate random positions?[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2009-08-06 UTCGood ★★★★
I expect this will be a very useful reference for newcomers to random variants, and probably for some not-so-newcomers as well.

I have a couple of quibbles, though, about probability. In my view, a good randomizing algorithm must ensure that all positions occur with equal probability (unless there's a good reason to do otherwise).

1st quibble: When same-color bishops are allowed, it's best to treat the bishops the same as any other piece, and simply not think about square colors when placing the bishops. If you use procedure 3.2, you'll skew the probabilities. For example, let's check the numbers for Modern Random Chess. [I'll use the notation nCr to denote the binomial coefficient 'n choose r'.] Suppose we place the bishops first, before any other pieces. We have 9 squares on which to place 2 bishops, so there are 9C2 = 36 possible placements for the pair. Let's see how these stack up in terms of color configuration, noting that the first rank has 5 dark and 4 light squares. There are 5C2 = 10 placements with both bishops on dark squares, 4C2 = 6 placements with both on light squares, and (5C1) (4C1) = 20 placements with one bishop on each color. But procedure 3.2 generates dark-dark placements with probability 1/4, light-light placements with probability 1/4, and light-dark placements with probability 1/2. This means that light-light placements will occur 50% more often than they should, and the others will occur less often than they should.

2nd quibble: With the constraint that the king must be placed between the two rooks, it's dangerous to place one type of piece before the other as in procedure 4.2–4.3. In Fischer Random Chess, for example, there are 108 positions with the white king on b1, 168 with the king on c1, 204 on d1, 204 on e1, 168 on f1, and 108 on g1. But if the king is placed first, it goes to any of these six squares with equal probability. (Note also that the Game Courier preset uses this method; thus FRC as implemented in Game Courier is biased toward positions with the kings on the flanks.) It's safer to leave the kings and rooks until the end as in 4.1.

Slide-shuffle. Variation of Shuffle Chess with special castling. (8x8, Cells: 64) [All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2009-07-30 UTC
My reply to George Duke's last comment will be offtopic on the Slide-shuffle page, but I'll post it anyway.

First, at least they're covering it!  As one who enjoys both chess and many of its variants, I'm glad that this event is held, and I'm glad that it's reported on.

Certainly the interjection of 'not the pawns' was not the most marvelous piece of prose ever written, and I too derived brief amusement from imagining the many permutations of eight identical pawns.  But presumably the author was simply attempting to clarify that pawns are not shuffled together with the pieces -- i.e. you never get pawns on the back rank and pieces on the second.

More importantly, the ChessBase article does not claim that Fischer was the first to propose randomized starting positions.  It simply states (correctly) that FRC/Chess960 was originally proposed by Fischer.  Remember that the purpose of this article is to report on a particular event in Mainz, not to provide a lengthy and exhaustive treatise on the history of every chess variant with any similarity to the one being played.

There's no disinformation here.

Fischer Random Chess. Play Bobby Fischer's randomized Chess variant on Game Courier. (Recognized!)[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2009-04-10 UTC
I agree with José Carrillo's suggested code, except that I think the rooks will need to be placed using first and last instead of left and right. With this modification it seems to work.

FischerRandomnew[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-08-15 UTC
The Mainz Chess Classic has begun today (or perhaps yesterday, since as I write this it's already tomorrow in Germany), but according to the official site, the Chess960 championship won't begin until Thursday.

Of course this match alone can tell us only about Svidler and Aronian, but this match is not taking place out of the blue. Lékó became the first Chess960 champion by defeating Adams in 2001. Svidler won the title from Lékó in 2003, and has defended it against Aronian in 2004 and against Almasi in 2005. I've read that the challenger must qualify by winning an open tournament, but it's harder than it should be to find such information from official sources.

It seems to me that Svidler's status as Chess960 champion is more legitimate than that of either Kramnik or Topalov as Chess champion.

Rococo. A clear, aggressive Ultima variant on a 10x10 ring board. (10x10, Cells: 100) (Recognized!)[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-07-23 UTC
The answer to all four questions is 'yes'.

1-2: The rules on this page state quite clearly, 'Swaps with Swappers may be combined with other captures.' Also, the animated illustration unambiguously shows a Chameleon swapping with a Swapper and capturing a Withdrawer, a Long Leaper, and an Advancer in the same move.

3: The only requirement for promotion is that the Cannon Pawn's move end on the 9th or 10th rank. There is no restriction on where the move must begin. Therefore a Cannon Pawn may promote after moving along the 9th rank.

4: A move to an edge square is permitted only when necessary for a capture. Moves from edge squares are unrestricted. Suicide by an immobilized piece on an edge square is surely not a move to an edge square, and is therefore permitted.

Dimension X. Chess on two planes - one with the usual chess pieces, the other with spooky trans-dimensional pieces with strange interactions. (8x8x2, Cells: 128) [All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-06-23 UTC
It certainly is a very interesting game, and the problems were fun to solve. I wonder how well the experience of solving them will translate into success on the board.

I have one question, which for some reason I didn't think about until now. The starting position on the FIDE board has the familiar mirror symmetry, while the Dimension X board has rotational symmetry. Thus the full starting position is asymmetric. Is there a reason for this? I would expect this asymmetry to introduce an imbalance (probably only a small one, since the trans-dimensional pieces need several moves to cross the board). It looks as though the white trans-dimensionals may find it easier to attack on the kingside, and the black ones on the queenside.

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Thomas McElmurry wrote on 2006-06-18 UTC
I think that the bug described by Greg is somehow a result of the site's
move last August.  If I'm not mistaken, it is only comments made before
2005-08-27 that have this problem.

If you posted such a comment, you can 'edit' it, and simply resubmit it
without making any changes.  The HTML will then be displayed properly.

Fischer Random Chess. Play Bobby Fischer's randomized Chess variant on Game Courier. (Recognized!)[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-03-25 UTC
First I'll cite some sources. This method has been described by Hans Bodlaender, and it is closely related to the quasistandard numbering system devised by Reinhard Scharnagl.

Suppose we place the bishops first. There are 4 squares available to each bishop, and therefore 4*4 = 16 ways to place the pair. Next we place the queen on one of the 6 remaining squares. Then the knights; there are 5*4/2 = 10 ways to place the two knights on the five remaining squares. Finally three squares are left for the king and rooks, and there is only 1 way to place them, since the king must be between the two rooks. Thus there are 16*6*10*1 = 960 possible positions.

The important point is that, in the above counting, the number of placements available to any given piece type is independent of where the preceding pieces were placed. For example, once the two bishops are placed, there are 6*10 = 60 ways to place the remaining pieces, and this is true whether the bishops were placed on a1 and f1, or on d1 and e1, or wherever. Thus, by placing the bishops first, we select one of 16 classes of positions, with the same number of positions in each class. It is therefore 'safe' to place the bishops first.

By contrast, if we place the king first, then the number of possibilities for the remaining pieces depends on where the king is placed. If the king is on b1, then one rook must be on a1, and the other can be anywhere from c1 to h1. Thus with the king on b1 there are 1*6 = 6 ways to place the rooks. But if the king is on c1, there are 2*5 = 10 ways to place the rooks, and if the king is on d1, there are 3*4 = 12 ways to place the rooks. (Also the number of possibilities for the bishops depends on how the preceding pieces are distributed between the two colors of squares.) By placing the king first we select one of 6 classes of positions, but the various classes contain different numbers of positions, and therefore this method skews the probabilities.

Thomas McElmurry wrote on 2006-03-25 UTC
I was reading about GAME Code in the Developer's Guide, and following its
advice I looked at the Pre-Game code for FRC.  It appears that this preset
does not generate the 960 starting positions with equal probability.  Of
the 960 possible positions, 216 have the white king starting on b1 or g1,
336 on c1 or f1, and 408 on d1 or e1.  But the preset places the king on
these six squares with equal probability.

The easiest way to generate all 960 positions with equal probability is to
place the bishops first, then the queen and knights, and finally the king
and rooks.

Chess Variant Pages Rating System. Missing description[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-03-24 UTC
Good point. It's true that ambivalence is only one possible cause of neutrality. Perhaps I should have said '... to express ambivalence or indifference,' although one who is indifferent toward a game is perhaps less likely to want to comment at all than one who is ambivalent.

If it's the choice of words that bothers you, I readily concede that 'Neutral' is not the best possible word for this new rating. 'Average' is significantly better, but still not perfect.

On another topic, I'm not sure I like the proposed popularity ranking. I'm guessing that under this system, the most 'popular' items on these pages would be the Rules of Chess FAQ, an old flame war regarding the Gothic Chess patent, and Navia Dratp.

Thomas McElmurry wrote on 2006-03-24 UTC
In the previous thread, Christine Bagley-Jones wrote:
i think the rating system in place is just fine, what is the point of 'neutral', what is that, it isn't even a rating, and isn't 'none' pretty much the same.
I will address the second, fourth, and fifth independent clauses of this sentence.

2. The point of a 'neutral' or 'average' rating is to allow users to express ambivalence.

4. Correct. As the system now stands, anyone can skim the rules of a game, think about it for thirty seconds, and proclaim that it's the best thing ever. But someone who has played a game numerous times, or analyzed in detail, and comes to the conclusion that it's nothing special (neither very good nor very bad) has no way to express that opinion and have it taken into account in the computation of the game's average rating. The fact that 'Neutral' or 'Average' is not a rating in the current system is the primary reason why change is desirable.

5. Correct. 'None' is not at all the same as 'Neutral' or 'Average'. 'None' is not a rating, communicates nothing about the user's opinion of a game, and has no effect on the average/overall rating. But a neutral rating would communicate something (i.e. that the user considers the game to be neither very good nor very bad) and does affect the overall rating.

In my opinion, in order for a rating system to be useful, it must include one rating which corresponds to neutrality, and at least two ratings on each side, so that both positive and negative opinions can be expressed with various degrees of intensity. The current system satisfies neither of these criteria and is therefore not useful. The proposed system satisfies both, and I think it could be useful if used properly (a big 'if'). It's interesting to note that the labels (ranging from 'Poor' to 'Excellent') are still biased toward boosting people's egos, but this is relatively unimportant: the meaning of the ratings is carried by their underlying numerical values, as long as it is clear which is the neutral rating.

Index page of The Chess Variant Pages. Our main index page.[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-03-23 UTC
I agree that the ratings system could use more options. In my view it should be possible to give a neutral rating, as Jeremy Good suggests, and to give a negative rating that is not the worst possible rating. I would like to see something like Awful, Bad, Neutral, Good, Excellent (with numerical values of -2, -1, 0, +1, +2) or perhaps even Awful, Bad, Poor, Neutral, Fair, Good, Excellent (-3, ..., +3).

Game Courier Tournament #2. Sign up for our 2nd multi-variant tournament to be played all on Game Courier.[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-03-22 UTC
Actually, Joe, by my count you can have eighth place all to yourself, due
to the Sonneborn-Berger tiebreaker.  I'll just sit back here in ninth and
wish our game of Maxima had gone differently.

Further congratulations to Gary Gifford for an impressive 11/12

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Thomas McElmurry wrote on 2006-03-18 UTC
Of course, when you play against Topalov, you will find it very difficult
to defend correctly after he sacrifices both of his rooks.

BishopsA game information page
. Commercial four-player game.[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-03-14 UTC
I see nothing inappropriate with using the word 'ugly'.  I share the
anonymous poster's opinion of the graphic, primarily because of the
garish colors.  But I have no objection to the appearance of the board and
pieces in the photograph on the linked page.

Rating your own game, however, really is inappropriate.  And I don't
think you'll find many people willing to pay nearly fifty dollars merely
for the right to find out whether a game is good.  To suggest that we
should do so takes a great deal of chutzpah.

About Game Courier. Web-based system for playing many different variants by email or in real-time.[All Comments] [Add Comment or Rating]
Thomas McElmurry wrote on 2006-03-11 UTC
That did it. The background field is now filled in in Opera, and the new setting was saved when I submitted a move.

I had thought it was only the colors in shogi-simple.png that bothered me, but I think you're right about the thick borders. I'm currently using shogi-blue.png in one of my games; it's equally simple, but the more sedate colors and the thin borders are a vast improvement in my opinion.

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