Talk:Lucena position

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[edit] straighforward win

I don't get "or else compel Black to give up his rook for it. Either result will leave White with an overwhelming material advantage and a straightforward win." If blackexchanges rook by pawn, black will be left with king alone, whereas white has king plus rook, and I though king+roook alone wasn't enough for checkmate, so, why does white win? drini ☎ 00:36, 20 May 2005 (UTC)

King and Rook vs King is an elementary mate. See if you can find how to mate with K and R v K in the Vikipedia. If you can't, do Gmail search (for Gmail users) or just ask me at whitekings@gmail.com
Submitted by J.L.W.S. The Special One on 18 July 2005
Also see checkmate. I've been meaning to put the technique for the elementry checkmates there, but I haven't gotten around to it. Bubba73 15:31, July 18, 2005 (UTC)
King and Rook vs. King is an easy win because the superior side can put the inferior side in Zugzwang and slowly squeeze the opponent's king into a corner with or without checks. Interestingly, if the side with only the king was allowed to pass (unless he's in check), then K+R vs K would be a draw. This is because in some positions, the superior side must make a waiting move, and if the inferior side would pass, then the superior side has nothing better than to make another waiting move (or pass himself), ad infinitum.
But what the article doesn't say is that, in some cases of K + R + P vs K + R, White must sacrifice the rook in order to win by queening. This results in a king and queen vs king and rook endgame which is anything but straightforward. Even masters have had to concede draws because they were not able to find the winning moves. Worse, some of those positions require over 40 moves before the superior side can force capturing the rook (or checkmate) against perfect play. This makes it relatively easy to hit the 50 move rule against a strong defender. Aragorn2 23:16, 18 June 2007 (UTC)
You are right about the side with the pawn sometimes having to sacrifice the rook in order to queen the pawn, and then win the Q vs. R endgame. I seem to remember that there is an example of that at Rook and pawn versus rook endgame, but I'm not sure. Bubba73 (talk), 23:30, 18 June 2007 (UTC)

[edit] Board position error

" 1.Rd1+ Ke7

   2.Kc7

gets nowhere (these moves are given in algebraic chess notation). Black can simply harass the white king with checks, and White makes no progress:

   2. ... Rc2+"

This doesn't match the board position shown, because it obviously results 3. Rxc2. I'm not familiar with this exact position, but someone who is ought to fix this up.

It looks OK to me, since the white rook moves to d1 on the first move, do it can't take the black rook on c2. Bubba73 (talk), 17:54, 1 June 2006 (UTC)

[edit] fourth or fifth rank?

The article now says "It is important for White's rook to go to the fourth or fifth rank; the fourth rank is considered the most elegant solution to the Lucena position." It seems to me that going to the fifth rank doesn't work as well. From the position, if 2. Rd5 then 2... Ke6. If the rook stays on the fifth rank (e.g. 3. Rb5 or 3. Rg5) then 3... Kd7 and white has not made progress. According to the endgame tablebase, after 2... Ke6, the best move is to bring the rook to the fourth rank with 3. Rd4. Bubba73 (talk), 21:55, 20 July 2006 (UTC)

The defensive king wants to be on the 7th rank: Black loses a tempo bring it back. (If Black strays too far, White can hide his K on the same file as the enemy K.) The move that prolongs resistance is not always the move that offers the most resistance. Put down the database & pick up Averbakh, Levenfish & Smyslov, or (if you MUST have a database-checked reference) Nunn's wonderful _Secrets of Rook Endings_. Billbrock 01:08, 22 July 2006 (UTC)

[edit] prononouncation?

The Immortal Game says it is Loo-THAY-na. this says Lou-CHAYN-uh. Which is right? Bubba73 (talk), 00:22, 12 January 2007 (UTC)

I asked a foreign language professor, and he said:
Italian is Lu-Chain-a
Castillian Espanish is Lu-Thain-a
Messican Espanish is Lu-Sane-a. Bubba73 (talk), 01:14, 14 January 2007 (UTC)
And Lucena was Spanish, so TH it is. Bubba73 (talk), 03:01, 16 January 2007 (UTC)