The Chess Variant Pages
Custom Search



Enter Your Reply

The Comment You're Replying To
H.G.Muller wrote on 2008-04-24 UTC
Indeed, my method is very time consuming. But I am still developing it, and
hope to make it more efficient. (For instance, I have not really
established what the optimal time control is to play these games. I am
using 40/2' with fairy-Max now, and 4/1' for my better engine Joker, but
it turns out that Joker finds the same Pawn-odds score at 40/10' as at
40/2'. If that would be true for all scores, I could speed the process up
by a factor 6!)

I currently have one dual-core PC entirely dedicated to Chess testing
(running 24/7). And I consider fairy-piece values one of the spear points
of my research. I have too many spear points, though: I develop two Chess
engines, micro-Max and Joker, also in variant versions, am currently the
main contributor to the WinBoard open-source GUI (and in particular the
only one that cares about variant support). I want to write a Shogi
engine, and develop a much faster end-game-tablebase builder. I could use
an extra computer, but I want to postpone my next buy until I can get an
8-core Nehalem. Because I want to develop a new SMP algorithm for tree
search that scales better on large numbers of cores, and I really needs a
machine to test this on. So for the time being, I will have to do with my
2.4GHz Core 2 Duo.

But eventually I will do most fairy pieces. I will probably convert Joker
to handle fairy pieces as well, as it can reach the same quality play in a
fraction of the time. If you have a computer (which is likely, since you
post here), you could easily do such tests yourself too, however. It is
harder on the PC than on the tester! It is just a matter of letting it
run, and once a day look at the result, set up a new position and start a
run for that.

I am currently running a test with 2 Ministers against 2 High Priests
(starting at the A and C positions of Capablanca Chess, so in a context of
all normal Chess pieces). This seems a pretty even battle, In fact, after
62 games, the High Priests are even leading (26+ 22- 14=, 53.2%). I guess
I will let it run overnight. But they are very close, so the High
priestess is also more a Rook replacement than a Bishop replacement. My
Rook opening value on 10x8 is only 475. So 625 is even on the strong side
for a Rook. (Why do you find that surprising? A Rook on 10x8 has a MAXIMUM
of 16 moves, and most will be blocked on a non-empty board. All 16 moves of
Minister and High-Priest are unblockable.)

I have not tried your leaper replacements for Bishop and Rook yet, but
some time ago I very precisely tested a similar piece, F+D, because I
wanted it to investigate pair bonuses for color-bound pieces (and F+D is
color-bound). A pair of these pieces tested nearly as strong as a pair of
Knights, perhaps a quarter Pawn weaker (this was on 8x8, though). This
would make it 290, as my Knight is 300 on 10x8. I don't know yet,
however, how much of this is pair bonus. But if a color-bound piece with 8
unblockable moves can be wrth as much as a Knight (at least, in a pair),
the non-colorbound pieces F+A and D+W must be similar or better, and thus
good Knight replacements.

It is funny that a pair of the F+D, which is the (color-bound) conjugate
of the King, is worth nearly a Knight (when paired), while a non-royal
King is worth significantly less than a Knight (nearly half a Pawn less).
But of course a Ferz is also worth more than a Wazir, zo maybe this is to
be expected.

Edit Form

Comment on the page Great Shatranj page

Quick Markdown Guide

By default, new comments may be entered as Markdown, simple markup syntax designed to be readable and not look like markup. Comments stored as Markdown will be converted to HTML by Parsedown before displaying them. This follows the Github Flavored Markdown Spec with support for Markdown Extra. For a good overview of Markdown in general, check out the Markdown Guide. Here is a quick comparison of some commonly used Markdown with the rendered result:

Top level header: <H1>

Block quote

Second paragraph in block quote

First Paragraph of response. Italics, bold, and bold italics.

Second Paragraph after blank line. Here is some HTML code mixed in with the Markdown, and here is the same <U>HTML code</U> enclosed by backticks.

Secondary Header: <H2>

  • Unordered list item
  • Second unordered list item
  • New unordered list
    • Nested list item

Third Level header <H3>

  1. An ordered list item.
  2. A second ordered list item with the same number.
  3. A third ordered list item.

Alt text for a graphic image

A definition list
A list of terms, each with one or more definitions following it.
An HTML construct using the tags <DL>, <DT> and <DD>.
A term
Its definition after a colon.
A second definition.
A third definition.
Another term following a blank line
The definition of that term.