Talk:Chess960 starting position

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[edit] Move to Wikibooks?

I saw a "move to Wikibooks" proposal, but this appears to be an encyclopedia article, not a Wikibooks article. It's not so much a "how to do something" as a compare-and-contrast of different systems. If there's a critical need to move it out, I'd like to hear why.

[edit] Bodlaender improvement

It's straightforward to reduce the average number of dice rolls for Bodlaender's method to 6.2. Instead of re-rolling 5s and 6s until something else comes up, re-roll once and use the following scheme:

  • 5 followed by 1 to 3 -> 1
  • 5 followed by 4 to 6 -> 2
  • 6 followed by 1 to 3 -> 3
  • 6 followed by 4 to 6 -> 4

I'm not sure whether to add this to the article, considering Wikipedia:No original research. On one hand, I imagine that it's been thought of independently by many. On the other, I haven't so far found it with a quick look on Google.

I'm in the process of thinking up what might be a 'perfect' dice-rolling algorithm, i.e. have the smallest possible average number of rolls while still generating each position with equal probability. Watch this space.... -- Smjg 19:11, 5 January 2007 (UTC)

[edit] Rovida's method

I edited the section, which previously claimed the method required four to six dice rolls, to five to six. There are three places where a roll need not be required (king on b1 or g1 so only one square available for a rook, or KQR all on same colour so only one square for same-coloured bishop), but only one of these can happen. 91.105.47.39 11:10, 26 July 2007 (UTC)

[edit] WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 07:56, 10 November 2007 (UTC)

[edit] drawing method

Here is a minor tweak to the Coffin and Scharnagl drawing method.

  1. Place the eight white non-pawn pieces in a bag, plus one white pawn.
  2. Draw pieces one by one. If it's not a pawn, place them on squares a1, b1, c1, ... h1. When you draw the pawn, put it on the second rank in front of the piece just placed. If the first piece drawn is the pawn (so there is no "piece just placed" to put it in front of), put the pawn back in the bag, shake, and start over.
  3. If the bishops are on the same color, and the pawn is on a different color, then swap *right* bishop with the piece diagonally behind and one file to the *right* of the pawn. If the pawn is on the right side of the board (h2), swap the right bishop with the piece on the left corner ( a1 ). (Now the bishops should be on different colors).
  4. If the bishops are on the same color, and the pawn is also on that same color, then swap the *left* bishop with the piece immediately behind the pawn. (Now the bishops should be on different colors).
  5. If the king is not between his rooks, swap the king with the closer rook.
  6. Place black pieces in mirror image and place remaining 7 white pawns.

It seems to me that this is much faster than diddling around with dice or coins or cards.

Yes, totally original research.

Assuming the pieces come out of the bag with equal probability, does this correctly give equal probabilities to all 960 starting positions? --68.0.124.33 (talk) 20:42, 26 February 2008 (UTC)