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'The champion has the combined moves of rook and knight. The centaur has the combined moves of bishop and knight.' - D. Pietro Carrera, 1617
<p>So the earliest variant gives the name Centaur to the other piece! Also, many people here follow Adrian King in calling the man-horse piece (K+N) a Centaur.
Nice to see you moving forward with your dream. Best regards!
To Greg Strong: of course you are right with your historical hints. There might be some remarks to be added in the CRC description. The CRC text should be extended, if there would be enough interested readers. To Greg Strong and David Paulowich: indeed there are more traditional names for C (Chancellor) and A (Archbishop). But those names do not correspond to the pieces: nor to their gaits nor to their symbols. I have tried to design more intuitive gait related symbols and noticed, that the names would not be helpful for newcomers to the Capablanca extended piece set. So I proposed names (partially already used differently in other context) to enhance the readability of CRC board positions to interested people. But that approach is only a suggestion, carefully keeping the same initial letters e.g. to stay compatible within X-FEN. To all posters here at CRC until now: thank you for your interest and encouraging words!
Good to see someone taking up the suggestion inspired by Grotesque Chess. I'm not keen on the names here either, my favourites being Marshal and Cardinal, but I'm getting used to such 'agreements to differ'.
Sometimes I wish Christian Freeling had used 'Marshalls' and 'Capablancas' in Grand Chess. Naming the pieces after two grandmasters would save us from endlessly debating the spelling of Marshal(l).
Just a small aesthetic observation about the graphic for the Archangel. Swords being short-range weapons, angels are also known to carry spears which have longer range. To carry over the motif from the Centaur, it could be a horseshoe with two crossed spears. Or the angelic theme might be further emphasized with a pair of wings and two crossed spears.
To Larry Smith: I have asked some interested people to send me some icon proposals. They should be not too complicated, differ sufficiently from existing and be related to the pieces' gaits. But I have not got some really convincing. Nevertheless if one has an exiting idea ...
Reinhard, I've worked up an example with two crossed spears and a pair of wings flanking a halo. You should be able to view it below: http://users3.ev1.net/~llsmith/home/angel_w.gif
I'm working on a Game Courier preset for this game, but I've hit a snag. So far, I have code that creates a random position, and I have code for checking whether all Pawns are protected, and I can also check the Levenshtein distance between a given setup and Gothic Chess. The problem is that PHP, which Game Courier is written in, gives it only 30 seconds to find a valid setup, and in each test, it has run out of time before finding one. So what I need is some shortcut for either selecting valid setups or screening out invalid ones. What might be ideal is to have a database of valid setups, each keyed to a single number, and then Game Courier could just pick a single random number, fetch the corresponding setup, and skip the tedious iterative process of randomly placing pieces until a valid setup is found. Another possibility would be to filter out a number of bad setups with wildcard filters, which would be faster than checking whether each Pawn is defended, but it would require appropriate filters. Does anyone have anything I could use without having to do all the preparation work myself?
Greg Strong wrote on Sun, Feb 27, 2005 08:23 PM UTC:Fischer Random Chess has the 960 legal starting positions numbered, and has the details on how to find a position from it's number, and how to find the number based on the position. Capablanca Random Chess could benefit from such a system. Besides making it easier to identify starting positions, it would also solve Fergus' present dilema. If a position can be determined from a position number, all that would be required is generation a random number in the valid range. For a good description of how FRC identifies positions by number, see: http://frcec.tripod.com/fischerrandomchessstartingpositions/
Why does each Pawn need to be defended at the initial set-up? This seems to be an arbitrary rule. There are many good Chess games where each and every Pawn is not defended at the start. In fact, these un-defended Pawns can create a nice area of early contention in play. Is there an actual 'flawed' setup, resulting in the loss of the game for one or the other player?
To Larry L. Smith: Well I know, that e.g. Shogi starts with three undefended pawns. Nevertheless the game has survived for long. But proposing new chess variants is mostly running against immense critic. So there are voices, which claims that most of the randomized positions were unplayable. I do not believe that at all, but I think it could help, to select just those positions, which are positionally more balanced. That lead to write down the additional rule of initially placing the Archbishop and Queen on different colored squares and to select only positions with all pawns defended. Of course this will reduce the genuine 48,000 possibilities to some more than 20,000. But this is still enough to avoid any creation of big opening libraries. So applying the rule might be skipped, but using it would help to make the variant more attractive to critic chess enthusiasts. Thus it has become part of my proposal.
To Greg Strong and Fergus Duniho: I have not awaited, that CRC would cause that quick your experiments to create those starting positions. Because of that I have not yet published a procedure, which would show how Smirf managed that problem and how to standardize the number to position relation. It obviously is not well known, that it has been me, who invented and introduced the numbering schema for Chess960. Beside of that numeric relation I have worked out a two table look up scheme which is fitting on to one single page to be used in chess clubs to have all Chess960 starting positions immediately at hands. For CRC a solution is of course not that easy. But if you are interested in that, I could post code snippets, where those positions are created from a given number. When Smirf is starting, it quickly creates an array of valid position numbers by probing all 48,000 and filtering the valid into an array of some more than 20,000 entries, what overmore allows to index those array with a short int, which is good for some pseudo random number generators, selecting later a randomized valid starting position. Another solution could be to use 6000 char constants, where the mass of 48,000 bits could be used to encode the precalculated validity of the appropriate number.
//=====================================
// CRC / Chess960 Position Generator
//=====================================
// reference implementation (C) 2005 by
// Reinhard Scharnagl, Munich, Germany
//=====================================
#include < string.h>
#include < stdio.h>
#define TXT_LIM 160
static char FenZone[TXT_LIM];
// insert a symbol into FEN-String
// -------------------------------
// color could be:
// col < 0 => not specified
// col == 0 => bright square
// col == 1 => dark square
void PlaceIntoFEN
(int cntFree, char symbol, int fieldColor)
{
for (int pos = 0, free = 0; ; ++pos) {
if (fieldColor < 0 || ((fieldColor ^ pos) & 1)) {
if (!FenZone[pos] && cntFree == free++) {
FenZone[pos] = symbol;
break;
}
}
}
}
// generating of FEN strings
// -------------------------
// nr could be
// nr >= 0 creating Chess960 position (1 ... 960)
// nr < 0 creating CRC position (1 ... 48000)
const char *GetFen(int nr)
{
// knight distributions over 5 free squares
static const int knight_pos[10] = {
3, // xx--- (binary encoded)
5, // x-x--
9, // x--x-
17, // x---x
6, // -xx--
10, // -x-x-
18, // -x--x
12, // --xx-
20, // --x-x
24 // ---xx
};
// clear the working area
int bit, pos = TXT_LIM;
while (--pos >= 0) { FenZone[pos] = '\0'; }
// test whether CRC is requested
bool istCRC = (nr <= 0);
if (istCRC) {
nr = -nr;
bool q_first = ((nr % 2) != 0);
nr /= 2;
PlaceIntoFEN(nr % 5, q_first ? 'q' : 'a', 0);
nr /= 5;
PlaceIntoFEN(nr % 5, q_first ? 'a' : 'q', 1);
nr /= 5;
}
PlaceIntoFEN(nr % 4, 'b', 0);
nr /= 4;
PlaceIntoFEN(nr % 4, 'b', 1);
nr /= 4;
PlaceIntoFEN(nr % 6, istCRC ? 'c' : 'q', -1);
nr /= 6;
pos = knight_pos[nr % 10];
for (bit = 5; --bit >= 0; ) {
if ((pos & (1 << bit)) != 0)
PlaceIntoFEN(bit, 'n', -1);
}
PlaceIntoFEN(2, 'r', -1);
PlaceIntoFEN(1, 'k', -1);
PlaceIntoFEN(0, 'r', -1);
int width = istCRC ? 10 : 8;
char *pC = &FenZone[width];
*pC++ = '/';
for (pos = width; --pos >= 0; ) {
*pC++ = 'p';
}
for (pos = 4; --pos >= 0; ) {
*pC++ = '/';
*pC++ = (char)('0' + width % 10);
}
*pC++ = '/';
for (pos = width; --pos >= 0; ) {
*pC++ = 'P';
}
*pC++ = '/';
for (pos = 0; pos < width; ++pos) {
*pC++ = FenZone[pos] ^ ('a'^'A');
}
strcpy(pC, ' w KQkq - 0 1');
return FenZone;
}
// test output
int main(void) {
puts('first Chess960 positions');
for (int nrFRC = 0; ++nrFRC <= 5; ) {
puts(GetFen(nrFRC));
}
puts('first CRC positions');
for (int nrCRC = 0; ++nrCRC <= 5; ) {
puts(GetFen(-nrCRC));
}
return 0;
}Reinhard, if you could provide me with a list of all valid CRC positions, I could store it as an array and use it for randomly selecting a position. You can email it to me at the address found by clicking on my name.
It looks like I won't need a list. It was timing out on me before because a bug was causing an infinite loop. It was checking for 'not ATTACKEDBYW' instead of 'not fn ATTACKEDBYW', which means it was applying 'not' to the function name instead of to the function itself. This gave the same result every time, leading to an infinite loop. As soon as I fixed the bug, it worked, and it gave me a position with all Pawns defended. But I think I will still optimize this by created a special DEFENDED function that more quickly checks whether a Pawn has a defender. As for comparing the setup to the Gothic Chess setup, I was thinking of calculating the Levenshtein Distance (which is the minimal number of characters you have to replace, insert or delete to transform one string into another) and rejecting any with a distance of 3 or closer. This would be making use of PHP's levenshtein function, which I have passed along to GAME Code. Or should I simply count the number of positions that are the same?
Just curious, why 3 or fewer? Rather than zero?
To Mark Thompson: three always is a good number. We have so much possible positions in CRC, so it does not hurt to skip some to avoid any conflicts with Gothic Chess. Live and let live. To Fergus Duniho: it seems as if you would use a very complex method to detect invalid starting positions. I will add a more simple method in short to the reference code I have posted here yesterday. Thus one will be able to see, that generating valid CRC positions only is neither a run time problem nor too complex to be programmed.
//========================================
// Valid CRC / Chess960 Position generator
//========================================
// Reference Implementation, (C) 2005 by
// Reinhard Scharnagl, Munich, Germany
//----------------------------------------
// Correction 2005-Feb-28 (GC-Nearness)
//========================================
#include < string.h>
#include < stdio.h>
#define TXT_LIM 160
static char FenZone[TXT_LIM];
// insert a symbol into FEN-String
// -------------------------------
// color could be:
// col < 0 => not specified
// col == 0 => bright square
// col == 1 => dark square
void PlaceIntoFEN
(int cntFree, char symbol, int fieldColor)
{
for (int pos = 0, free = 0; ; ++pos) {
if (fieldColor < 0 || ((fieldColor ^ pos) & 1)) {
if (!FenZone[pos] && cntFree == free++) {
FenZone[pos] = symbol;
break;
}
}
}
}
// generating of FEN strings
// -------------------------
// nr could be
// nr >= 0 creating Chess960 position (1 ... 960)
// nr < 0 creating CRC position (1 ... 48000)
const char *GetFen(int nr)
{
// knight distributions over 5 free squares
static const int knight_pos[10] = {
3, // xx--- (binary encoded)
5, // x-x--
9, // x--x-
17, // x---x
6, // -xx--
10, // -x-x-
18, // -x--x
12, // --xx-
20, // --x-x
24 // ---xx
};
// clear the working area
int bit, pos = TXT_LIM;
while (--pos >= 0) { FenZone[pos] = '\0'; }
// test whether CRC is requested
bool isCRC = (nr <= 0);
if (isCRC) {
nr = -nr;
bool q_first = ((nr % 2) != 0);
nr /= 2;
PlaceIntoFEN(nr % 5, q_first ? 'q' : 'a', 0);
nr /= 5;
PlaceIntoFEN(nr % 5, q_first ? 'a' : 'q', 1);
nr /= 5;
}
PlaceIntoFEN(nr % 4, 'b', 0);
nr /= 4;
PlaceIntoFEN(nr % 4, 'b', 1);
nr /= 4;
PlaceIntoFEN(nr % 6, isCRC ? 'c' : 'q', -1);
nr /= 6;
pos = knight_pos[nr % 10];
for (bit = 5; --bit >= 0; ) {
if ((pos & (1 << bit)) != 0)
PlaceIntoFEN(bit, 'n', -1);
}
PlaceIntoFEN(2, 'r', -1);
PlaceIntoFEN(1, 'k', -1);
PlaceIntoFEN(0, 'r', -1);
int width = isCRC ? 10 : 8;
char *pC = &FenZone[width];
*pC++ = '/';
for (pos = width; --pos >= 0; ) {
*pC++ = 'p';
}
for (pos = 4; --pos >= 0; ) {
*pC++ = '/';
if (width >= 10) {
*pC++ = '1';
}
*pC++ = (char)('0' + width % 10);
}
*pC++ = '/';
for (pos = width; --pos >= 0; ) {
*pC++ = 'P';
}
*pC++ = '/';
for (pos = 0; pos < width; ++pos) {
*pC++ = FenZone[pos] ^ ('a'^'A');
}
strcpy(pC, ' w KQkq - 0 1');
return FenZone;
}
// check if FEN is valid for CRC
// -----------------------------
bool IsValidCRC(const char *pFen)
{
// to be avoided GC position
static const char *gcArray = 'rnbqckabnr';
// pawn covering pieces (like a rook)
static const char *covNear = 'rcqk';
// pawn covering pieces (like a bishop)
static const char *covDiag = 'baqk';
// pawn covering pieces (like a knight)
static const char *covDist = 'nac';
int size = (int)(strchr(pFen, '/') - pFen);
int diff = 0;
for (int n = size; --n >= 0; ) {
// different to GC?
if (pFen[n] != gcArray[n]) {
++diff;
}
// unprotected pawns?
if (strchr(covNear, pFen[n]))
continue;
if ((n+1) < size && strchr(covDiag, pFen[n+1]))
continue;
if ((n-1) >= 0 && strchr(covDiag, pFen[n-1]))
continue;
if ((n+2) < size && strchr(covDist, pFen[n+2]))
continue;
if ((n-2) >= 0 && strchr(covDist, pFen[n-2]))
continue;
return false;
}
// GC-near position?
if (diff < 3 && size == (int)strlen(gcArray)) {
return false;
}
return true;
}
// test output
// -----------
int main(void)
{
puts('\nfirst Chess960 positions');
for (int nrFRC = 0; ++nrFRC <= 10; ) {
printf('(%03d) %s\n',
nrFRC, GetFen(nrFRC));
}
puts('\nfirst CRC positions');
int cntValid = 0;
for (int nrCRC = 0; ++nrCRC <= 48000; ) {
const char *pFEN = GetFen(-nrCRC);
bool valid = IsValidCRC(pFEN);
if (nrCRC <= 32) {
printf('(%05d %s) %s\n',
nrCRC, valid ? 'ok' : '--', pFEN);
}
if (valid) {
++cntValid;
}
}
printf('\n%d valid CRC arrays\n', cntValid);
return 0;
}<pcode>
Results of the CRC reference code:<br>
<br>
first Chess960 positions<br>
(001) bqnbnrkr/pppppppp/8/8/8/8/PPPPPPPP/BQNBNRKR w KQkq - 0 1<br>
(002) bqnnrbkr/pppppppp/8/8/8/8/PPPPPPPP/BQNNRBKR w KQkq - 0 1<br>
(003) bqnnrkrb/pppppppp/8/8/8/8/PPPPPPPP/BQNNRKRB w KQkq - 0 1<br>
(004) qbbnnrkr/pppppppp/8/8/8/8/PPPPPPPP/QBBNNRKR w KQkq - 0 1<br>
(005) qnbbnrkr/pppppppp/8/8/8/8/PPPPPPPP/QNBBNRKR w KQkq - 0 1<br>
(006) qnbnrbkr/pppppppp/8/8/8/8/PPPPPPPP/QNBNRBKR w KQkq - 0 1<br>
(007) qnbnrkrb/pppppppp/8/8/8/8/PPPPPPPP/QNBNRKRB w KQkq - 0 1<br>
(008) qbnnbrkr/pppppppp/8/8/8/8/PPPPPPPP/QBNNBRKR w KQkq - 0 1<br>
(009) qnnbbrkr/pppppppp/8/8/8/8/PPPPPPPP/QNNBBRKR w KQkq - 0 1<br>
(010) qnnrbbkr/pppppppp/8/8/8/8/PPPPPPPP/QNNRBBKR w KQkq - 0 1<br>
<br>
first CRC positions<br>
(00001 --) aqbbcnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/AQBBCNNRKR w KQkq - 0 1<br>
(00002 ok) qbbacnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/QBBACNNRKR w KQkq - 0 1<br>
(00003 --) abbqcnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/ABBQCNNRKR w KQkq - 0 1<br>
(00004 ok) qbbcnanrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/QBBCNANRKR w KQkq - 0 1<br>
(00005 ok) abbcnqnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/ABBCNQNRKR w KQkq - 0 1<br>
(00006 --) qbbcnnrakr/pppppppppp/10/10/10/10/PPPPPPPPPP/QBBCNNRAKR w KQkq - 0 1<br>
(00007 --) abbcnnrqkr/pppppppppp/10/10/10/10/PPPPPPPPPP/ABBCNNRQKR w KQkq - 0 1<br>
(00008 --) qbbcnnrkra/pppppppppp/10/10/10/10/PPPPPPPPPP/QBBCNNRKRA w KQkq - 0 1<br>
(00009 --) abbcnnrkrq/pppppppppp/10/10/10/10/PPPPPPPPPP/ABBCNNRKRQ w KQkq - 0 1<br>
(00010 --) baqbcnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BAQBCNNRKR w KQkq - 0 1<br>
(00011 --) bqabcnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BQABCNNRKR w KQkq - 0 1<br>
(00012 ok) bbqacnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBQACNNRKR w KQkq - 0 1<br>
(00013 --) bbaqcnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBAQCNNRKR w KQkq - 0 1<br>
(00014 ok) bbqcnanrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBQCNANRKR w KQkq - 0 1<br>
(00015 ok) bbacnqnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBACNQNRKR w KQkq - 0 1<br>
(00016 --) bbqcnnrakr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBQCNNRAKR w KQkq - 0 1<br>
(00017 ok) bbacnnrqkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBACNNRQKR w KQkq - 0 1<br>
(00018 --) bbqcnnrkra/pppppppppp/10/10/10/10/PPPPPPPPPP/BBQCNNRKRA w KQkq - 0 1<br>
(00019 ok) bbacnnrkrq/pppppppppp/10/10/10/10/PPPPPPPPPP/BBACNNRKRQ w KQkq - 0 1<br>
(00020 --) bacbqnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BACBQNNRKR w KQkq - 0 1<br>
(00021 ok) bqcbannrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BQCBANNRKR w KQkq - 0 1<br>
(00022 --) bbcaqnnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCAQNNRKR w KQkq - 0 1<br>
(00023 ok) bbcqannrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCQANNRKR w KQkq - 0 1<br>
(00024 ok) bbcnqanrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCNQANRKR w KQkq - 0 1<br>
(00025 ok) bbcnaqnrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCNAQNRKR w KQkq - 0 1<br>
(00026 ok) bbcnqnrakr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCNQNRAKR w KQkq - 0 1<br>
(00027 ok) bbcnanrqkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCNANRQKR w KQkq - 0 1<br>
(00028 --) bbcnqnrkra/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCNQNRKRA w KQkq - 0 1<br>
(00029 ok) bbcnanrkrq/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCNANRKRQ w KQkq - 0 1<br>
(00030 ok) bacbnnqrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BACBNNQRKR w KQkq - 0 1<br>
(00031 ok) bqcbnnarkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BQCBNNARKR w KQkq - 0 1<br>
(00032 ok) bbcannqrkr/pppppppppp/10/10/10/10/PPPPPPPPPP/BBCANNQRKR w KQkq - 0 1<br>
<br>
21821 valid CRC arrays<br>
</pcode>
<P>Reinhard Scharnagl wrote:</P>
<BLOCKQUOTE>
it seems as if you would use a very complex method to
detect invalid starting positions. I will add a more simple method in
short to the reference code I have posted here yesterday. Thus one will be
able to see, that generating valid CRC positions only is neither a run time
problem nor too complex to be programmed.
</BLOCKQUOTE>
<P>No, my method is not so complex, and once I fixed the infinite loop bug, there were no run time problems. I have since modified it to your exact specifications, but here is how the method you're commenting on worked.</P>
<OL>
<LI> Clear the first rank.</LI>
<LI> Select a random setup per your instructions.</LI>
<LI> Check whether each Pawn is defended, and if any is undefended, start over.</LI>
<LI> Generate a string of the setup and calculate its Levenshtein Distance from the setup for Gothic Chess. If the Levenshtein Distance is too small, start over.
</OL>
<P>The Levenshtein Distance is the minimal number of operations it takes to change one string into another, counting insertions, deletions, and substitutions as operations. Your instructions use the Hamming Distance, which is the number of substitutions it takes to change one string into another string of the same length. Although calculation of the Levenshtein Distance is more complicated than calculation of the Hamming Distance, I don't have to worry about that, because it is handled by a PHP function. Since almost all setups will pass, using the Levenshtein Distance doesn't cause any appreciable increase in time.</P>
<P>Using the Hamming Distance, as your instructions use, has the advantage of being easier for humans to calculate, but as long as computers do the calculations, the more sophisticated Levenshtein Distance might be preferable. Whenever they are unequal, the Levenshtein Distance will be smaller than the Hamming Distance. This would be useful if you want to avoid setups that differ from Gothic Chess not only by a couple substitutions but also by moving one piece in a way that shifts much of the lineup one space left or right but keeps most of the order intact. For example, 'BRNBQCKANR' has all Pawns defended, and its Hamming Distance from Gothic Chess is 8, but its Levenshtein Distance is 2, because I got it by simply deleting a Bishop and inserting it on the left side.</P>
<P>Your reference code has answered one question I had. I wasn't sure whether you meant to exclude setups whose Hamming Distance from Gothic Chess was less than three or less than or equal to three. From your code, it looks like less than three. So you're excluding any setup with a Hamming Distance of two or less. Given the same pieces, you will never have a Hamming Distance of only 1. So what you are excluding is limited to only setups that differ by switching the places of two pieces.</P>
<P>The preset I made currently uses the Hamming Distance and follows your instructions to the letter for generating a random position and excluding invalid setups. If you ever decide that you would rather use the Levenshtein Distance, all I will have to do is replace the hamming operator with the levenshtein operator in my code.</P>
To Fergus Duniho: you are obviously unsure on the grade of distinctness between valid CRC arrays and the GC starting position. So let us do a historic approach and try to calculate the distance between GC and historic 10x8 starting arrays as from Carrera, Bird or Capablanca. I think that there are more than three reported arrays from those people. When it has been possible to patent GC being only slightly different to those positions, it should be sufficient to demand only the smallest there occurring distance. Comparing the GC array 'RNBQCKABNR' to one reported as from Bird 'RNBCQKABNR' there is a Hamming distance of only two. But I am not sure, if this Bird's array has been specified that way - I am missing still the original source. If the smallest distance indeed should be greater than three, the code I have supplied has to be changed appropriately. May be variant experts could help to solve that question doubtlessly.
<BLOCKQUOTE>
you are obviously unsure on the grade of distinctness between valid CRC arrays and the GC starting position.
</BLOCKQUOTE>
<BLOCKQUOTE>
Comparing the GC array 'RNBQCKABNR' to one reported as from Bird 'RNBCQKABNR' there is a Hamming distance of only two.
</BLOCKQUOTE>
<P>That is correct. In this instance, the Levenshtein Distance is also 2.</P>
<P>Based on this, I see three options for you.</P>
<OL>
<LI> Exclude just the Gothic Chess setup.</LI>
<LI> Exclude any setup whose Hamming Distance from Gothic Chess is 2 or less.</LI>
<LI> Exclude any setup whose Levenshtein Distance from Gothic Chess is 2 or less.</LI>
</OL>
<P>Each subsequent option excludes more setups than the previous one. Your CRC proposal currently uses the second of these options.</P>
To Fergus Duniho: Well, if that is indeed the historic array of Bird, then a Hamming distance of at least three (as I have specified) would be more than sufficient. So I would not change that demanded difference of three. I would like to keep the Hamming distance, because shifting a group of pieces has an immense effect on the properties of a starting array. And I think that the so created valid CRC arrays obviously are distinct from GC.
Gothic Chess, being a derivative of Capablanca Chess, has no exclusive claim upon Capablanca Chess. Neither does it have a claim upon Fischer's Random Chess. Thus how does combining these two independent forms, which it has absolutely no claim upon, be actionable on the part of Gothic Chess?
To Larry L. Smith: It seems you are targeting, that CRC should not care at all on Gothic Chess. May be you could be right. But I do not intend to have any unnecessary quarrel about that theme, so I prefer to exclude some few (15 arrays) positions. I think the remaining 21821 starting arrays nevertheless should be sufficient for CRC.
Today I have sent in an updated version of the CRC proposal. I hope that it could replace the old initial version soon and that it then would be much better to read. I want to thank here Mr. Bodlaender and all others, who help together to publish those new proposals within this 10-chess contest and for the big efforts they are putting into this huge chessvariants project! P.S.: Are there any ideas how to accomplish changed contents to become exchanged here on this site?
Are there any changes to the rules that I need to change in the Game Courier preset?
To Fergus Duniho: No, the rules still are the same, the overall layout should have been improved. According to your CRC Game Courier Preset I am still not familiar how to randomize or to preset a special position number. It seems to always create the same array.
You might not be giving it the opportunity to change its seed for the random number generator. It will normally pick a fresh seed at the beginning of each new game, but you may sometimes have to refresh the page to make this happen. It has no facility for letting you choose the array you want. It always automatically generates a random array.
Are there any ideas how to accomplish changed contents to become exchanged here on this site?
A) Sorry for not having accomplished to update the CRC content here. B) There is a first public beta of Smirf (about 1.3 MB), unrestricted until 2005/06/30. Of course this chess program is subject to further improvements: http://de.geocities.com/rsmuenchen/ The program should be handled intuitively. But also notice: a) the board could be turned by clicking on a corner of the board, b) in edit mode castling rights easyly could be switched by clicking the file letters near the involved rooks. This simplifies a consistent management of castling rights especially with Chess960 positions (maybe an idea for Arena), c) you will find possibilities to select how move possibilities should be shown or not in the help menu, d) double clicking on a move of the list of possible moves will show that move and preselect it, e) double clicking on a move of the game list will reposition the game to the related situation.
Greg Strong wrote on Tue, Apr 26, 2005 12:03 AM UTC:Excellent ★★★★★The Beta of SMIRF is quite nice! Good user interface, nice set of features, and intelligent play. It would be nice if you would consider making it open-source.
Well, I am still no fan of Open Source here. Nevertheless I have published the details of the new TMCI protocol, thus making it freely usable. That is, because I am arguing for open standards and interface descriptions.
This looks like a good game. I like Fischer Random Chess, as well as some of the variants played on this board with these pieces. So I expect the combination to be good.
a) CRC (Capablanca Random Chess) will be supported soon by http://www.brainking.com . b) There is a time limited Beta of SMIRF FullChess program (full functional) playing a lot of variants including CRC, for download see http://www.chessbox.de/Compu/schachsmirf_e.html . Regards, Reinhard Scharnagl.
Greg Strong wrote on Thu, Sep 1, 2005 01:17 AM UTC:I have been trying this version, but have some difficulties... I have been using Janus Chess for testing. First, no matter which timing mode I use, the program always seems to make its move in less than a second. Second problem is that I do not see where you decide which side(s) are computer controlled. After a manual move is entered, it starts thinking, but I see no way to make the computer play itself... Otherwise, the program looks nice. Keep up the good work!
Hi Greg, > I have been trying this version, but have some difficulties... > I have been using Janus Chess for testing. yes, from time to time there is a fully testable Smirf version, which is only time limited by an attached testing key. > First, no matter which timing mode I use, the program always seems > to make its move in less than a second. That is Smirf's behaviour when the testing key is wrong or timed out. The current beta package has a working key valid until end of September. So I prosume you are not testing the current package or have it repeatedly installed into an already existing Smirf folder where an outtimed key has been stored in its ini file (and would not be replaced). Thus repeat the installing procedure but delete any existing Smirf INI file before. In the reduced mode you are describing, Smirf abilities still could be inspected, but thinking time and some abilities are reduced. This is because Smirf is intended to become Shareware later. > Second problem is that I do not see where you decide which side(s) > are computer controlled. After a manual move is entered, it starts > thinking, but I see no way to make the computer play itself... Well, Smirf does not play against itself. It is planned to install a special form of remote playing ability to enable playing with other 10x8 chess programs. That would help to also test different engine versions to hopefully detect progresses. There is a check box 'automatic'. Switch it off, and you could enter as much moves as you like without Smirf's answering. You also could switch into the edit mode and e.g. switch the active color. > Otherwise, the program looks nice. Keep up the good work! Same for your ChessV! I hope for this there would be a remote protocol installed, too (and a beep). Ed Trice has proposed one, but it seems not to be sufficiently flexible to also support other 10x8 Chess variants. Thus I try to implement a compatible protocol superset. Do you have matching ideas? Regards, Reinhard.
Hello Greg Strong! I see, that you have tried to test out a more recent SMIRF version. First download the actual beta 1.26 from http://www.chessbox.de/Compu/schachsmirf_e.html . If you want to install it into an existing directory, make sure, that this would be empty (no INI file might exist there). The current beta has a free testing key including October. To start a game with white, simply enter a move. To make Smirf use the white pieces, simply press the right button (with the flash symbol). I just have played some Janus Chess games with it and ChessV, SMIRF has become really strong. ;-) Reinhard.
Greg Strong wrote on Wed, Oct 19, 2005 04:27 PM UTC:Reinhard: Thank you for the information, and for your continued work on SMIRF! It is much easier for me to develop and test ChessV now that I have another strong Universal Chess Program against which to test it. I'll download the new version you mention and check it out soon... Also, you should be aware that the last two versions of ChessV (0.8 and 0.81) have a really bad bug which results in the program making really stupid moves on rare occasions. I've fixed this, but haven't gotten around to uploading a correction. In the next couple of days I will upload a new version... Out of curiousity, have you looked at the source code to ChessV? And, if so, has it veen of help to you? Just curious. I would also be curious to know what technologies SMIRF uses (such as null move, forward pruning, quiescent search, singular extensions, etc.) Thanks! Greg
Hi Greg, the only chess program I have inspected ever has been an early version of GNU. I then immediately decided not to use anything from it. So SMIRF is completely self developed. But some strategies as known and documented in literature have influenced me. Actual today is SMIRF 1.28. As far as I can see SMIRF has a very different data structure. It is a flat interpreted 15x12 array. The pieces consist of bit encoded properties and are members of two double linked always sorted lists. There are two concurring pruning strategies: intelligence feed back (self invented) and controlled single nullmove (less important). There is only ONE engine playing a lot of 8x8 and 10x8 chess variants compatibly including traditional chess rules, Fischer castlings and the extended Capablanca piece set. One exceptional extension is Janus Chess with its symmetric castling. The evaluation (still very weak) is not done at quiet nodes but at deescalated nodes, which means, that also positional combinations are terminated instead of only piece exchanges.
There now a german language description is available at wikipedia: http://de.wikipedia.org/wiki/Capablanca-Random-Chess
material values- all pieces Capablanca Random Chess http://www.symmetryperfect.com/shots/values-capa.pdf
Hi Derek, your values now are also shown at my site at http://www.chessbox.de/Compu/schachveri1_e.html, around where you also could find my reworked piece value derivation.
Thank you for publishing my results. Doing so implies that you have some trust in my calculation method even as it differs from your own and the English-German language barrier creates apprehension. We are all trying to reach the same destination (accurate relative piece values). We just have different reasons for taking different roads in pursuit of it. Unfortunately, the subject is just too complicated to be approached exclusively from math and geometry as applied to games. Where value judgments are necessarily required (for instance, in determining the details of a formula and what 'looks right' based only upon estimated material values of pieces in well-established games that seem to work well), philosophy becomes involved. Thereafter, the dangerous line between 'the unreasonable effectiveness of mathematics' and 'the unreasonable ineffectiveness of philosophy' (to quote Dr. Steven Weinberg) is approached. For what it is worth, your set of material values for pieces in CRC fall into the safe, flat scale between the relatively compressed scale of Trice and the relatively expanded scale of Nalls. So, if there is anything at all reliable within the work of any of the 3 of us, then your calculations for pieces in CRC are either the most accurate or the 2nd most accurate.
Richard,
Here is some information I have on the value of the Carrera pieces which I came up with when designing my own Carrera-esque opening setup:
Here is a table of four different derived values for the pieces, obtained from three different chess variant playing computer programs and one other source.- Sam
Piece ChessV SMIRF Zillions Aberg Pawn 1.000 1.000 1.000 1.000 Knight 2.500 3.056 2.362 3.000 Bishop 3.250 3.690 2.859 3.300 Rook 4.700 5.604 4.262 5.000 Queen 8.750 9.558 7.060 9.000 Archbishop 6.500 6.838 5.127 6.800 Marshall 8.250 8.832 6.659 8.700 The ChessV numbers were obtained by looking at the source code for ChessV. The SMIRF values, derived by Reinhard Scharnagl for his SMIRF chess computer program, were obtained from this web page. The Zillions of Games' values were obtained by looking at the values of pieces by right-clicking on them after loading a fresh Schoolbook zrf file, and before moving any pieces. Aberg's figures come from right here on the variants server.
All four agree on the following:
The verdict is still out on some other exchanges:
- A bishop is about a half-pawn more valuable than a knight.
- Two knights are worth more than a rook.
- An archbishop is worth more than two knights.
- A marshall is worth more than an archbishop.
- A queen is worth more than a marshall.
- Two rooks are worth more than a queen.
- A marshall is worth more than a rook and knight.
- A marshall is worth more than two bishops.
- A rook and knight are worth more than an archbishop.
- A rook and bishop vs. a queen.
- A rook and bishop vs. a marshall.
- A bishop and knight vs. an archbishop.
- Two bishops vs. an archbishop (Two bishops are probably worth more).
Hi Sam, please note, that SMIRF's evaluation model currently has been changed (and as I hope simplified) concerning it's third basic mobility component. Thus the values you mentioned are no more identic to the actual, sorry. (The third component is still subject to change, I tend to simplify it even more.)
P=1.000, N=3.053, B=3.500, K=3.722, R=5.815, A=6.858, C=8.870, Q=9.617
See for it at the: SMIRF-Site
P=1.000, N=3.053, B=3.500, K=3.722, R=5.815, A=6.858, C=8.870, Q=9.617
See for it at the: SMIRF-Site
Hi Derek, SMIRF is still beta. It is designed to be shareware in the form of donationware. On its download page there is the possibility to make a donation via paypal to support the project. Any serious donation will be answered by sending back a permanent personal key, which will stay valid for follow up versions. Without a key SMIRF will always answer immediately, thus not showing its full strength. See: SMIRF download page. Because of Gothic's patent, GC currently is not supported directly, nevertheless any 8x8 or 10x8 position could be set up manually.
RULE TO BE ADDED After experimenting with CRC for several months I detected that there could be some special positions, which might be too advantageous for white. They belong to a subclass of positions, where the pair of bishops is neighboured. Thus I as the author have decided to add the following selection rule: 'positions with neighboured bishops have to be avoided.' There 12118 positions still are remaining.
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Very nice! The author has done an excellent job of defining a Fischer randomization system for Capablanca's Chess (actually this piece mix goes back to the 1600s with D. Pietro Carrera -- see Carrera's Chess.) It is obvious to me that the design has been carefully considered from both a game-designer's perspective and a software developer's perspective.
I'm not sure I like the idea of renaming the pieces, though. There are already too many different names for these pieces, and I think the goal should be to standardize the names, and I believe Capablanca's names of Archbishop and Chancellor are probably the best choices.