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Comments by Samuel Trenholme

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Chess programs move making[Subject Thread] [Add Response]
Samuel Trenholme wrote on Tue, Sep 13, 2022 03:35 PM UTC:

A NNUE with an alpha-beta search is fine: Stockfish 15 is stronger than any other chess player in the world, either human or computer.

The main thing that is interesting with Alpha Zero is that it can play a super human game of chess with no human chess knowledge except the game's rules. So, for example, any opening or midgame strategy is has is not based on human play.

Game Courier User's Guide. How to play games with the CV Play-by-Mail system.[All Comments] [Add Comment or Rating]
Samuel Trenholme wrote on Wed, Jun 29, 2022 09:45 PM UTC:

To play games the way one plays correspondence games on lichess or, one simply has grace time without reserve time.


If we have no (0) reserve time (Edit: In other words, no “spare time”, no “min time”, no “extra time”, and no “bonus time”), and we have a grace time of 24 hours, this means, as soon as one moves, the opponent has 24 hours to reply to your move. If they fail to reply within 24 hours, they lose the game.

Lichess makes things simple by having no reserve time whatsoever, and having only the following settings for grace time (which is simply the time needed to make a move before losing the game on Lichess) in correspondence games:

  • 1 day
  • 2 days
  • 3 days
  • 5 days
  • 7 days
  • 10 days
  • 14 days
  • Untimed

So, for dealing with “this guy never moves once they are losing”, having a grace time of 14 days ensures that both people have plenty of time to make moves (especially in today’s world with smart phones everywhere), but that forgotten games are won by the last person to make a move before forgetting the game exists.

Ignoring “Min Time”, “Bonus Time”, and “Bonus Period”, “Spare Time” is, using a Fischer (increment) chess clock the amount of time given for the game, “grace time” would be 0 (since a simple Fischer clock doesn’t have this), and “extra time” would be the increment (the amount of time given for each move).

Let me explain this with an example. We have a game with 5 days (120 hours) of spare time, a grace time of 24 hours (1 day), and an extra time of 1 hour.

The clock starts, and Alice (white) is playing Bob (black).

  • Alice makes her first move as soon as the game starts. She now has 121 hours spare time: 120 hours at game start, then 1 hour added after making her first move.

  • Bob replies 23 hours later. Since he replied within 24 hours, he loses no spare time, but gets one hour of extra time. So now Alice and Bob have 121 hours of spare time. Grace time is always the same for each move.

  • Alice is busy the next day and needs 26 hours to reply to Bob’s move. The first 24 hours were against her grace time, so only the final two hours of her delay moving went against her spare time. She lost two hours of spare time (119 hours now), but gained one hour after making her move (so she now has 120 hours of spare time again; with grace time, if she doesn’t move within 144 hours, she loses).

  • Alice created a lot of tactical complications for Bob, so Bob needs 72 hours to reply to Alice’s move. 24 hours is grace time, so we only look at the remaining 48 hours when calculating spare time lost. Bob lost 48 hours spare time taking so long to make his move, but gains one hour after making his move. 121 hours - 48 hours (delay moving after grace time) + 1 hour (extra time) = 74 hours left (with the 24 hour grace time, Bob needs to make his next move within 98 hours or lose the game)

  • And so on.

(The time control that works best for me is 2 days: 48 hours to make a move or I lose. The problem with one day time controls without reserve time is that every day I have to make my move earlier in the day, but, with two days, if I make a move every day, it doesn’t matter what time of day I make the move. There are ways to have one-move-a-day without the issue of having to make my moves earlier and earlier each day, but our time controls are probably already too complicated).

ArchMage Chess. 10x10 30v30 Fantasy Chess. (10x10, Cells: 100) [All Comments] [Add Comment or Rating]
Samuel Trenholme wrote on Fri, May 20, 2022 07:22 PM UTC in reply to Fergus Duniho from 07:11 PM:

Summoning looks really overpowered, and we’re trying to figure out if we can keep the mechanic without it ruining the game.

Some ideas:

  • Summoning just puts a piece on the board once in the game, akin to Seirawan (Sharper) chess.
  • My proposal to give the other player an extra move after a summoning is done.

I mentioned Zillions, but, of course, Fairy Max might be able to implement the summoning mechanic to playtest just what compensation we need to give the other player when invoked (unrestricted extra move, restricted extra move, etc.).

Samuel Trenholme wrote on Fri, May 20, 2022 07:10 PM UTC in reply to Bn Em from 06:52 PM:

Since I didn’t make this clear: The opponent wouldn’t get to keep their extra move “in pocket”. When a summoning is done, the opponent then makes two moves immediately afterwards.

It’s true an extra move is very powerful, but having a replaceable piece which is only fully removed from the game when the summoner is captured is very powerful too. [1] If the two moves end up being too much compensation for the summoned piece, we can hobble that too (the extra move can not capture, one piece can not move twice, etc.)

I agree we need some playtesting to here to find out how much compensation we give the other player for the summoned piece getting placed on the board. It’s like changing the king’s move or how the pawns move: It changes the nature of the game enough that extensive playtesting is needed to see if it unbalances the game to the point it’s a forced win for the first player, or (especially if making the king too powerful) if it makes the game an easy draw.

This is also why I still like Zillions, some two decades after the program was last updated: Zillions is a relatively easy way to playtest game mechanics like this one.

[1] A game with summoning and drops can make the summoning less unbalanced too, since we can come up with some way of combining those mechanics to balance the summoning. Another option is to go the Seirawan route and only allow a summoning of a piece to be done precisely once.

Samuel Trenholme wrote on Fri, May 20, 2022 03:59 PM UTC in reply to H. G. Muller from 01:51 PM:

“I am starting to suspect that this summoning business will sort of spoil the game. Because you get the Demons back whenever you lose them, at the cost of only a tempo.”

One thought I have been having is to make a summon cost two tempo: You can summon a piece, but when you do, your opponent gets an extra move.

Let’s imagine, for the sake of simplicity, a Seirawan Chess variant where instead of the “add the piece when moving a piece in the back rank” rule, the knight can summon the Elephant (Seirawan’s nomenclature for the R+N Cardinal/Marshal) next to it, and a bishop can summon a hawk (B+N, i.e. Archbishop), but each time a summoning is done it costs two tempo.

Here’s how a game could start out:

  1. Nf3 d5
  2. E@g3 e5,Nf6

We could write the score like this too, if preferred:

  1. Nf3 d5
  2. E@g3 e5
  3. (Tempo lost after summoning) Nf6

Here, White opens with Nf3, Black responds d5

Next, White summons an Elephant on to g3 (I’m using Crazyhouse notation, which is fitting because Seirawan himself frequently plays Crazyhouse on Lichess). Because White has performed a summoning, Black now gets a bonus move, so Black moves e5 then Nf6.

If the other player responds to the summoning with a summoning as their first move, they don’t get the second bonus move. If they respond to the summoning with a summoning on their bonus move, the other player gets a bonus move, e.g.:

  1. Nf3 Nc6
  2. E@g3 E@b6


  1. Nf3 Nc6
  2. E@g3 d5,E@b6
  3. e4,d4

I think the summoning mechanic is very unique and creative, but it might give White a won game, but maybe we can hobble it to keep it usable.

Samuel Trenholme wrote on Thu, May 19, 2022 04:17 AM UTC:Good ★★★★

I think one thing the author may do until when and if this variant gets formally published here is to make a Zillions of Games implementation of it, then send an email to Ed van Zon to get the implementation published. There can be a long delay before a submission and its publication here, but Ed’s pretty good about publishing a submission within a week of its submission.

The hard part is taking all these rules and converting them in to Zillions’ quirky language. I enjoy doing it myself; it converts rules in to unambiguous machine-readable rules, and it allows people to play the variant themselves.

I would also change the name of the summoned pieces in to something like, oh, Dragon Horse and Dragon King, the Anglicized form of these pieces’ names in Shogi. I like the summoning tactic, but it’s an open question whether having it makes the White advantage overwhelming. People seem to enjoy Crazyhouse a lot over at Lichess, so I think this summoning mechanic can be very usable.

(I should also point out that Betza called what is the Jester here the “Waffle”)

Sovereign Chess. Ten neutral armies can be activated on this 16 x 16 board. (16x16, Cells: 256) [All Comments] [Add Comment or Rating]
Samuel Trenholme wrote on Sun, May 15, 2022 07:04 PM UTC in reply to Katie from 06:10 PM:

Replies like this will be empty if replying using the wrong password, or if replying as a guest. The workaround is to create an account, log in, and be sure to use the correct password.

Complementarity - Part I. With Short Range Project in mind, list of a highly specific set of pieces defined by simplest compounds.[All Comments] [Add Comment or Rating]
Samuel Trenholme wrote on Sun, May 15, 2022 09:50 AM UTC:Excellent ★★★★★

A while ago, I looked at 31 possible short range pieces. I have now expanded this research.

I have written a small C program which looks at all 16,777,215 possible leapers that move at most two squares. Some findings:

  • I expected around half of all possible pieces to be colorbound in some way. Wrong. 16,452,080 (over 98%) pieces are not colorbound.
  • There are 104 non-colorbound pieces with three moves, 2,512 pieces with four moves, and some 2,696,337 pieces with 12 moves.
  • Only 2,944 possible pieces are Bishop colorbound: These relatively few pieces can go to the same 32 squares a Bishop can go to.

With some 16,452,080 non-colorbound pieces, if we replace the knight, bishop, and queen with a random non-colorbound short leaper, that gives us 4,453,099,898,116,838,912,000 which is, what, 4 hextillion possible variants, and that’s keeping the king, pawns, and rook.

OK, if that’s not enough possible variants, we can also add the ability for a given random piece to be able to be a rider in any direction it can leap (e.g. a fers-rider is our bishop; a wazir-rider is a rook, and a knight-rider is, well, a knightrider), where we randomly choose, from all the moves a given leaper has, for it to be able to ride in a random number of directions. For example, if we look at the wazir, then randomly choose which directions it moves like a rook and which directions it can only move one square, we get 16 possible pieces. If we do this for all 16,452,080 non-colorbound short range pieces, we get some 282,232,643,280 possible pieces, just over 2 to the power of 38 (2^38 or 2 ** 38 in Python notation).

This means an 8x8 board with random non-colorbound pieces and using a standard chess set has some 6,344,961,231,517,063,209,074,884,200,517,463,972,290,560,000 possible variants (the pawns and kings can keep their moves), just over 2 to the power of 152.

ChessVA computer program
. Program for playing numerous Chess variants against your PC.[All Comments] [Add Comment or Rating]
Samuel Trenholme wrote on Wed, May 11, 2022 08:21 AM UTC:Excellent ★★★★★

I don’t know the correct procedure to file a bug report for ChessV, so I will just note the bug here.

Description of bug

ChessV does not use the standard Chess960 numbering scheme for opening setups. See for the reference of correct number to starting position. In particular, ChessV is off by one (Position 0 in the official spec is position 1 in ChessV, etc.)

Steps to reproduce

Open up ChessV. Choose Fischer Random Chess. When it asks for an expected setup, choose setup #692.

Expected results

The opening setup should be RBBQKNNR (Mongredien chess)

Actual results

The setup is BRQKNNRB


Position 693 is the Mongredien setup in ChessV, so one just needs to add 1 to the official position number to get the corresponding position in ChessV.

Position 518 (519 in ChessV) is the standard chess starting position.

Turtle Shell Chess. Chess on a 33344-33434 tiling. (5x7, Cells: 64) [All Comments] [Add Comment or Rating]
💡📝Samuel Trenholme wrote on Wed, May 11, 2022 07:54 AM UTC:

This is my attempt to put a chess variant on a non-standard tiling. While the hex tiling has been fairly extensively explored for chess variants, and there are a few games using a triangle tiling, and Tony Paletta has explored the rhombille tiling, and George Dekle has explored a few tilings, this is the first chess variant I know of that uses a demi-regular tiling (Onyx, a Hex-style connection game, uses a similar archimedean tiling).

Any comments or civil criticism is welcomed.

Until this variant gets published, guests can see a Zillions implementation of the game is at Zillions of Games; that zip file includes a PDF with full game rules.

ChessVA computer program
. Program for playing numerous Chess variants against your PC.[All Comments] [Add Comment or Rating]
Samuel Trenholme wrote on Sun, May 8, 2022 07:00 AM UTC:Excellent ★★★★★ continues to host the ChessV software, and, indeed, has been updated to have version 2.2 of ChessV. Should ever go down, this is an alternate download link.

Design Contests[Subject Thread] [Add Response]
Samuel Trenholme wrote on Fri, Apr 29, 2022 10:10 PM UTC in reply to Fergus Duniho from Thu Apr 28 01:43 AM:

I think another design contest would be nice. I like having the option of two different numbers; I could do something nice with 62 spaces if we need more submissions.

(This is the same Sam Trenholme who made Schoolbook a long time ago. I’ve given up on password recovery, so I’m just using a new account. As an aside, Gmail isn’t getting the verification emails.)

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