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Chessville
Chess
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The Lucena Position - Part 3 Achieving the Lucena Position by David Surratt
In Part 1 of our look at the famous Lucena Position, we reviewed the winning method. In Part 2 we looked at why White cannot win if the pawn is on the a- or h-files (and the exception to this exception!). Now let's take a look at the important question of getting to the Lucena position in the first place. Reuben Fine, in Basic Chess Endings, says:
"If the Pawn is on the fifth
rank with its King near it and Let's take a look at a position:
In this position the Black king is indeed cut off, and the pawn is on the fifth rank, so it follows that, according to Fine's rule, White should win. Let's take a look, with a little help from my friend Fritz... 1.Ka5 White wants to get the King in front of the pawn in order to evict the Black rook. 1...Ra8+ If Black tries to just leave the rook on the b-file with 1...Kd7 , White proceeds 2.b6 Kd6 3.Ka6 and the rook will soon be forced out. 2.Kb6 Rb8+ After all, Black wants to keep the White king out from in front of the pawn. This next maneuver is reminiscent of White's winning technique once the Lucena position has been reached and the King is emerging from behind his pawn.
3.Ka6 Ra8+ Once again 3...Kd7 is met with 4.b6 Ra8+ 5.Kb7. 4.Kb7 Ra4
The rook has been evicted, and the king is in front of the pawn. White wins. 5.b6 Rb4 Black can also try 5...Kd7 but White just continues on about his business with 6.Kb8 etc. 6.Ka7 Ra4+ 7.Kb8 Ra2 8.b7 Kd7
The basic Lucena position has been achieved. White wins. Fine offers another, more complex rule about reaching the Lucena position: "If the Pawn is on the third or fourth rank and its King is near it, White can always force a win if and only if the Black King is cut off at a distance of three files from the pawn (b- or g-pawn) or two files from the pawn (c, d, e, or f-pawn). If the Pawn is on the second rank, and Black's King is on the fourth or fifth, White wins if an only if the King is cut off at a distance of five files from the Pawn." Let's take just one quick look at this rule:
In this position, if it is White to move, then White wins: 1.Re1 Remember Fine's rule: the Black king must be cut off by at least three ranks, so that is the first order of business. 1...Kf5 2.Kc4 Rc8+ 3.Kd5
Threatening to push the Black king even further away from the pawn. 3...Rb8 4.Rb1 White could interpose a rook check and push the Black king over to the g-file, but it just delays the inevitable by one more move. 4...Rd8 5.Kc6 Rc8+ 6.Kb7 Rc2
Now it is time for White to push his pawn; the Black king is too far away to help. 7.b5 Ke6 8.b6 Ra2
If instead Black continues approaching with the king with 8...Kd7 then 9.Rd1+ forces him back to the e-file, and hastens White's victory by a few moves. 9.Kb8 Kd7 10.Rb4 Kc6 11.b7 Kd7
Black has to back off momentarily, else after say, 11...Rh2 12.Rb1 Rh4 13.Ra1 Rh8+ 14.Ka7 Rh7 15.Ka8 and Black will have to surrender his rook. 12.Rd4+ Ke6 12...Kc6 13.Kc8 wins. 13.Kc7 Rc2+ 14.Kb6 Rb2+ 15.Ka6
This position should look familiar by now: White has his rook on the 4th rank, the Black king is cut off, and White's king is finishing emerging from inn front of his pawn. If you mastered the winning technique shown in Part 1, then you need no further explanation here. You will have to work the rest of the intricacies of Fine's rule out for yourself; Fine uses six and one-half pages to explain it! Here is another example of reaching the Lucena position:
White's best play is as follows: 1.Rf8 White has to keep the Black king away, and for that reason can't play 1.Kg6 Ke7. 1...Rf2 2.Kg7 Rg2+ Now if Black tries 2...Ke7 White has 3.f6+ Ke6 4.Re8+
3.Kf7 Rf2 4.f6 Rf1 5.Ra8 Time to activate the rook.
5...Rf2 Black really has nothing better than to sit on the f-file and make White prove it. 6.Kg7 Rg2+ 7.Kf8 Rf2 8.f7 Rf1 9.Ra4 "The rook needs to be on the 4th rank in order to provide shelter for the king..." Remember Part 1?
9...Rf2 10.Rd4+ and wins. Another important sequence to understand is Black's defensive technique known variously as the "Long-Side Defense" or the "Short-Side Defense" or simply, sideways checking. The gist of the idea here is for Black to get his king to the shorter side of the board (from the perspective of the pawn) and then use the threat of his rook harassing the enemy king with checks from the longer side of the board (along the ranks) to keep White from making any progress.. Sound confusing? Let's look at an example:
Black to move - mate is threatened! Which side should he head to? 1...Ke8 2.Ra8+ Kd7 looks a lot like the diagram at the start of our last example - which White won! Let's try the other direction... 1...Kg8 2.Ra8+ Kh7 3.Rf8
Now Black's rook heads for the "long-side" (a-file through e-file) checking position. Notice the "short-side" (g- and h-files) is where the Black king is. 3...Ra1 4.Re8 White seeks to block the coming checks with his rook. If instead White tries 4.Ke7 we get 4...Ra7+ 5.Ke6 (5.Ke8 Ra8+ 6.Kf7 Ra7+ 7.Ke6 Weren't we just here, a couple of moves ago?) 5...Ra6+ 6.Ke5 Ra5+ and where is all this getting White? Nowhere! Or 4.Ke6 Kg7 5.Rf7+ Kh6 6.f6 Ra6+ the infamous long-side checking I warned you about. 7.Ke5 Ra5+ 8.Ke4 Kg6 and again, White makes no progress. 4...Rf1
Preventing the pawn's advance. 5.Re7+ Kg8 6.Ra7 White doesn't seem to be making any progress here.
6...Rf2 7.Ra8+ Kh7 8.Ke6
At last the king emerges from the shadow of his pawn! But... 8...Kg7 ...once again prevents the pawn's advance. White can make no headway; the position is drawn. There is much more to this topic than can be covered here. I recommend the reader the following books as reference material for further study on your own:
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