Wednesday, September 26, 2007

Not Quite Lucena II

Not Quite Lucena positions feature the attacker's pawn on the sixth rank with his king in front of the pawn. They're quite common in practice. If you haven't already, I recommend reading my previous articles, Lucena I and Lucena II, before proceeding.



Today, we'll learn how to crush a couple inaccurate defenses. Defenders goof in over 80% of such positions. So my advice to you is to be patient until an opportunity presents itself, and then be swift in exploiting it!

Mistake #1: The defending king is on the eighth rank




Black to move. Black has a few defenses he can try:

1...Kg7 - Black places his king where it belongs, on the sixth or seventh rank. The refutation is simply 2.Rg2+!, beginning a Lucena maneuver.

1...Ra7+ - Black's best try is an active defense. This would work if the Black king were on the sixth or seventh rank, but now it fails to 2.Kf6 Ra6 3.Rd8+ Kh7 and with the Black king more than one file away, the win is inevitable. An important point is that 2...Kf8 was impossible due to 3.Rd8#.

1...Rg1 - Black mounts a passive defense, preventing a check on the g-file. In rook endings, passive defenses usually fail and this is no exception. 2.Ke8 Kg7 3.e7 and now either 4.Kd7 or 4.Rg2+ is unstoppable and wins.



White wins, with Black to move, if his rook's on any of the green squares. These squares (a) allow White to initiate a Lucena maneuver if Black moves his king to g7 and (b) prevent 2...Kf8 due to 3.Rd8#.

Mistake #2: The defending king is on the fifth rank




1...Kg6 - Black places his king where it belongs, on the sixth or seventh rank. The refutation is simply 2.Rg2+!, beginning a Lucena maneuver.

1...Ra7+ - Black's best try is an active defense. This would work if the Black king were on the sixth or seventh rank, but now it fails to 2.Kf8 Ra8+ 3.Kf7 Ra7+ 4.e7. The problem is, White's rook must stand alone, and a strong defense usually requires coordination between the rook and king.

1...Rg1 - Black mount a passive defense, preventing a check on the g-file. In rook endings, passive defenses usually fail and this is no exception. 2.Ke8 Kg6 3.e7 and now either 4.Kd7 or 4.Rg2+ is unstoppable and wins.



White wins, with Black to move, if his rook's on any of the green squares. These allow White to initiate a Lucena maneuver if Black moves his king to g6.

I hope you enjoyed this article and learned something, too. :)

2 comments:

Temposchlucker said...

Do you have Secret rook endings from Nunn? It is devoted to all rook+pawn vs rook positions.

likesforests said...

Wow! I didn't realize there was a whole book on Rook & Pawn vs Rook, but I'm not too surprised. Minev's Practical Rook Endings has much more detail than Pandolfini or Dvoretsky and yet it still reads like the Cliff Notes version of the ending. It can be very complex!

Competency and master are different goals, and I will settle for being competent at this ending. Dvoretsky says that requires knowing 40 or so positions. That's much more than the average player who thinks they can get away with just knowing the Lucena and Philidor techniques, but less than Secrets of Rook Endings or a tablebase contain.

Kasparov apparently owns the book that I'm using... Minev's Practical Chess Endings... and has committed all 52 positions to memory! It's his primary reference. So if I can just master its knowledge, I figure I'll be OK.