Sunday, October 28, 2012

Helpmate in 3 by G Paros 1933 Il Problema

Reproduced from the early collection of helpmates "Conspiracy" by Alain White, one of his Christmas series books.

This three-move helpmate shows great strategy culminating in a model mate. Every move is thematic. The Black queen prepares to flight-block her King, and has to take the scenic route e2, g4. There is a departure effect right on move 1, as The White King arrives on d5, a square formerly in check. Note moreover that the White knight is now pinned. On the next black move, Black arrives on g4. It is now time for the White king to perform a anticipatory unpin of the white knight. He goes to Kc4. Why does the white king not go to e6, the other available square? Because that is reserved for the mating piece. On Black's last move, the Black King arrives on f4 for his model mate. This horizontally unpins the White Knight, a nice effect. Se6 is a beautiful model mate. The whole thing works like a Swiss watch. The order of the moves is forced, and there is harmonious interaction between the white and black moves, and nice economy.

Roi accule aux angles

This problem of Sam Loyd is reproduced from Alain White's first Christmas book "Roi accule aux angles". I am not providing the solution of the two-mover puzzle this time. To solve it, there are two approaches. One is to note the name of the composer. Sam Loyd has the reputation of a great prankster. The last move you are likely to think of will be the key. Obviously, I solved this problem at a glance. Clue: Despite the overwhelming force available to white, his forces are tripping in each other's path. You need grand open spaces to mate, even to mate a king in a corner!

Rg2? is an interesting try but it fails. Black has two moves both of which defend against Qh8 mate and the threat of discovery by the king. 1..Qa8! keeps the defense of h8 and eyes the queen on a1, Notably 2.bxa8=Q is not even check with the rook on g2.... 1...Qc8 also works (since Her Royal Highness can interpose on c1)

The above should clue you to the key.

an ECHO in a study

The above is a White to play and draw problem created by Prokop. Please do not ask me about the dull R+2P vs R+P endgame draw if Black underpromotes. In the interest of art, let us have him be greedy to succumb to the quick stalemate.

Notice the two variations ending in Qxc4 and Qxc5. You may click on the last moves in the two variations. Notice how almost the entire position is shifted down one rank. This is called an ECHO in the field of chess composition.

In the famous Christmas Series of Alain White, one edition is devoted to Echoes. "It is natural that the echo has spread from the direct (mate in #n) problems to every other class of artistic chess creation. ....Up to recently only traces of the echo idea were apparent in the end game study. It is particularly the merit of F.J.Prokop that we have some brilliant examples also in this field. In his hands many a study gains quite an exceptional character which has neither predecessors nor any tradition in chess literature." Indeed, up until then, artists such as Havel produced echoes in orthodox n-mover form.

Subtle timing and strategy in long helpmate

Chris J Feather, a master of the helpmate, and a vocal critic of weak compositions, has nothing but praise for the strategy in this long helpmate by Babesi composed in 1955. "The best face of the long helpmate.", he writes in Black to Play - a monograph on helpmates, "Some subtle timing and a more dynamic use of the closed corner than in most such problems. The word 'miracle' used by one solver is hardly out of place. Goodness knows how many hours the genial and charming composer spent on this, but Alybadix" (a computer program to check soundness of fairy compositions) " needed 9 hours, 38 minutes, 3 seconds (with a 80486/33 processor).

Indeed, note how the Black king munches a White pawn creating tempi for the white pawn behind it, as it goes to b4, note how the white knight takes on g4 to create a spare move for white, as black's promoted rook is wheeled into place, and note the precise clockwork timing of everything, and I have passed over mentioning the first bishop underpromotion.

Saturday, September 29, 2012

A difficult two-mover

This is from my book "White to Play" by Alain White. First, note the set play. If BQ plays along diagonal, you have Qxh7 mate, and if QxQ Sf2 mate. Other black pawns are pinned or blocked, and if the bishop moves you have Qb1 mating.

So that is a block. Can you preserve the waiting nature of the problem with any quiet move? Try as you might, you cannot.

So please move the mouse over, or click on the 1.? to see the solution. After the key, white threatens Rg4 mating. We now have the changed mates or added mates, exd4 Qd5 mate, Kxd4 Qb4 is cute, original mates Qb1, and Qxh7 are still in play after the other two captures on d4 to prevent the threat.

The above kind of problem is called a block-threat. Very deceptive and very hard to solve, but with a sharp intake of breath or "aha" feeling when you solve it.

Friday, September 28, 2012

A staircase

In "Tasks: The cumulative principle in problem composition" republished as "Classic Chess Exercises", Alain White gives the above example of a staircase.

"Here we have another example of a consecutive White piece journey...The WQ starts from the ground floor of her house, and goes slowly upstairs to the very top. She then throws herself out of the window, to the street below, possibly with a view to suicide; and surprises herself as much as anybody else that by so doing she has really succeeded in mating her old enemy, the Black King, who has been kicking his heels on the street corner."

ha ha

Saturday, September 8, 2012

Lev Loschinski, Two-mover, Black Arrival Correction

Lev Loschinski was a master of composition. His name is pre-eminent like Comins Mansfield for the two-mover. However, he was equally great in the three-mover, in the modern as well as the strategic, discovered various new artisitic touches such as the Loschinski "magnet". Here, we see a elegant and spare setting for a two-mover featuring 'arrival correction', a term connoting the mechanism for separating the white mates, as explained below.

After the key (click on the 1.?), a random Black piece needs to arrive on d4 to prevent the threat (>2.Qxa7). However arrival of a powerless Black piece allows 2.Qxe2 mate. However, since the Black piece that arrives has powers to move and is not just a square-occupier, new mates are required and enforced thus:

1...d4 2,Qxe2? d3!! Therefore 2.Bc4# (Black pawn has interfered with the fourth rank)

1...fSd4 2,Qxe2 Sxe2 Therefore 2.Ra3# (Black line-opening third rank, valve closing 4th)

1...eSd4 2,Qxe2?? Therefore 2.Qa2# (Black line-opening third rank, valve closing 4th)

1...Bd4 Therefore 2.Qxe2# (Black bishop has interfered with the fourth rank)

1...Rd4 (Completing the Grimshaw (defintion: Two variations in which Bishop and Rook interfere with the other on the same square)) 2.Qxe2? Rc4, Therefore Rh6#(Black rook has vacated the h file (line-clearance) while BB's control of h6 has been interfered with, this is Grimshaw)

Helpmate in 18, White king check avoidance

Another helpmate for fun. Before the dark-square bishop can sacrifice itself at c7, W's king needs to be sheltered from check by the black rook. This means the light-square bishop has to come over to f1.

The whole timing and strategy, as Black's king takes just the pawns on b5 and b6 and gets checkmated on a4, by the newly promoted queen coming from c8 to a6, has strategic appeal that is classic helpmate more-mover.

Note the elegant timing of the released black pawn on b7, creating the self-block on b4 in the nick of time.

This was part of a nice article from Ljubomir Ugren (Zagreb) and Marko Klasinc -Ljubljana entitled "Rekordi (tasks) Pomocnog mata" in the April 1973 issue of Problem.

Wednesday, September 5, 2012

Tries in two-mover, "schnittpunkt" theme

In set play, we have 1...Sd6 (a self-block) 2.Sd3 mate (it is OK for White to interfere with the d-line because of Black's self-block on d6. White chooses to close exactly the same line on which Black piece lies like an X-ray).

The pair variation in set play is 1...Sf6, 2. Sg6 mate (White closing the sixth rank, since f6 is a self-block)

The theme of schnittpunkt is the a point where two lines intersect. Let us try 1. Bb1 (or 1.Bc2).Threat is Qe4. This Try crosses the critical square d3. All mates are set except for 1....Sd6! (Now the set mate attempt failes 2. Sd3 dis ch? 2 Kf5!! White is closing his bishop's control of f5 (which is not ok) at the same time he is closing the d file (which is ok).

The pair try is 1.Bh7. Again threat is Qe4. Black this time defends with 1...Sg6! Now white's set mate 2. Sg6 dis ch is not mate, since he is once again closing his bishop's control of f5 (2...Kf5!!), not OK!, whereas closing the sixth rank was ok because of the self-block.

The Key was 1.Kf3! Threat 2.Qh5

1...Sd6 2.Sd3

1...Sf6 2.Sg6

1..R(f,g)8 2.Rxe6

1...Se7 2.Rxe6

1...B(g1->any) 2.Qa1#

In other notes, these two published an Original joint problem in 1955 in "The Hindu", a newspaper which ran a chess problem column that was, after my Rice, Matthews, Lipton, a bit of a Indian weekend entertainment some decades ago. However, 1955 was even earlier than my time....

Self-mate in 28, with cross-checks

In a "self-mate", white plays first, but he is trying to force black to checkmate him, not to give mate.

Therefore, although White may mate in one by d8=Q, he is not interested. He goes about a particular sequence of moves, forcing Black to make "only" moves, as one rook climbs down the ladder, giving check and covering check continuously. It dies on g2, Black making tempo moves with h-pawns. The other White Rook plays up the same ladder, giving check and covering check, sacrificing itself symmetrically at b7, even as an under-promotion gives White tempo moves to allows Black to mate.

Count the number of checks.

Themes with multiple cross-checks are called Brede checks, a term introduced by Alain C. White of an Ellerman three-mover in a Good Companion folder.

Thursday, August 30, 2012

Black unpins White

Arnoldo Ellerman (12.01.1893-21.11.1969), an Argentine, was a prolific composer of two-movers. He showed many Black line-themes (interference and shut-offs) in the Good Companion problem folders. Here, the theme is Black unpinning White, not out of kindness, but to avert a threat. This will cause another defect in the Black position, allowing precisely separated mates.

1. Qh1! [ Threat >2. Qf3#]

1. ... Rd4 Interference with dark sq bishop allowing 2. Sf6#

1. ... Rc3 Interference with dark sq bishop allowing 2. Sf6#

1. ... Rd3 Interference unpin of white rook 2.Shut-off (of Rd3), discovered mate 2.Re3#

1. ... Bxe2+ 2. Bxe2# is not thematic

1. ... Rc4 Interference unpin of white rook 2.Shut-off (of Rc4), discovered mate 2.Re4#

1...Bb7 Withdrawal unpin of white rook 2.Shut-off (of Bb7), discovered mate 2.Re4#

1. ... Bc8 Withdrawal unpin of white rook 2.Shut-off (of Bc8), discovered mate 2. Re6#

1. ... Kg4 (a flight granted by key) 2. Qf3#

The beauty of the problem is the combination of the two ways in which a line-piece may be unpinned, by interference and by withdrawal. It will pay for newcomers to play over these beautiful variations.

Cross-checks, King flights, in the two-mover

Click on the 1.? after you have tried to solve it.

The main threat with the key is 2.Qxe4 mating, (the key paves the Queen's control on the e6 square initially obstructed). However, the main play is that the key sets up a surprising strong line of attack on the white-king, allowing the Black king to give as many as three discovered checks. These may be termed a royal battery, the King being the firing piece and the queen giving white check from the rear. For each, White's checkmating reply is separately forced as we shall see soon. This sequence where B gives W check, and W checkmates right back is called a cross-check. (As many as five cross-checks have been shown in a single problem, a "task".)

If 1...Ke6 ch, 2. Sc5 is dbl ch and mate. The knight blocks the discovered check of black, arriving on c5, it discovers double check from the light-sq bishop, and the king cannot move to the seventh rank, since the knight had also discovered the W Q's guard of e7!

If 1...Kg6 ch, 2.Se5 ch mates, (e5 interposes the check), g7 is not a run-out for His Majesty, since W Q's guard on g7 has been discovered, and B does not have QxS which is illegal(!) since Her Majesty is pinned upon this King flight by WR on g2.

If 1...Kxf4 ch, 2.Sd5 dbl ch mates (d5 interposes the check), it is dbl ch, discovered from the Rook battery down the f-file this time, and e3 square is diabolically covered by the checking Knight.

Slightly less thematic, but still cute, is the last variation 1...Qxf4, not a cross-check or a King flight. Now 2.Sb8 mates. The king cannot run to f4 on account of the "self-block", and the action to prevent the black rook line on the eighth rank is called a shut-off mate.

Wednesday, August 29, 2012

Helpmate in 28

This one is for sheer fun, possibly the longest helpmate ever devised.

Newcomers, please recall that in helpmates, Black moves first and is cooperating in finding a single variation in which white may deliver checkmate in the stipulated number of moves. However, neither side may move into check, (or move a pinned piece leaving their king in check, or otherwise make a illegal move). In the final checkmate position, standard rules apply.

Note: it is a bit unusual for Black king to be in check in a position, but it is Black to play first, and neither side may make a illegal move, so the first Black move is forced. The rest is forced by the logic that Black has to navigate the minefield of white pawn controlled squares, while creating a passer to promote to allow White to promote. All of this takes 28 dance steps.

Tuesday, August 28, 2012

Bristol Theme

This problem was composed in 1917. The first appearance of a long-range clearance move (a white piece making way for a like-moving white piece to barrel down the same line was shown by Frank Healy in a three-mover setting in 1861 in a composition tourney in Bristol. Hence the theme came to be known as Bristol.)

The key is somewhat surprising if you have not seen this type of paradoxical idea before. The bishop retreats all the way to the other corner anticipating someone else coming from h8 to b2. 1.Ba1. Black has no choice. 1...Kxg2. Now white promotes to queen. 2. h8=Q. Again, Black has no choice 2...Kf2. Now, we see the point of the clearance. 3. Qb2#. Note how the King at e4, the black pawn at g3, all have their roles in restricting the black monarch's freedom. There is one forced line of play throughout.

The Bristol theme here was characterized by Bh8->Ba1, and then Qh8->Qb2

For more examples with Bristol moves used multiple-times in the same problem, in post-key phase, in try play, or in helpmates, see the excellent ozproblems page on Bristol

Monday, August 27, 2012

Sam Loyd, puzzle king

The first thing you do in a "mate in two" problem, is the examine the "set" play. This means you pretend it is Black to move first, and you find checkmate moves for White

Set Play:

1. ... d5 2. Sc5#

1. ... b2, Sb4/a3/e3/e1 2. Q(x)b4#

1. ... Ra3/b2 2. S(x)b2#

In this problem, every legal black move has a White mate provided in the initial position. Such a position is called a "block". Sometimes, to preserve the character of a block problem, you try to find a quiet White move, that keeps Black in this trouble. Can we do that here? Let us see. If Bd1 moves, Black can now play b2, and there is no pin on the knight(S) at c2, no mate Qb4. If Bxc2, Sxc2. Strong checking moves by the Queen are useless, since 1.Qa7ch? Kb5 and the king escapes. The White rook cannot move gainfully. It releases the e-pawn 1...e5+ by Black would not be nice. How do we find a quiet move?

Some more terminology for future use. Neither the Black p at b3 nor S at c2 are pinned, but they can be said to be half-pinned. A great English composer Comins Mansfield, made many problems where the main line of play uses halfpins. Entire books have been written about problems with half-pins "Het Half-pin thema" in Dutch.

Have you solved it yet?

Sam Loyd was one tricky guy. The key move does not preserve the quiet. It introduces a threat. Such problems with a block in the set play and a threat in the "key" (the solution's first move) are called "block-threat" problems and are both rare and difficult to solve. Here the key is 1.Sa3! (>2. Threat Qa7#) (By covering b5, the threat is set up for the mate.) Here are the variations

1. ... Kxa3 2. Qa5/a7#

1. ... b2, Sb4/xa3 2. Q(x)b4#

1. ... Rxa3 2. Sb2#

Saturday, August 25, 2012

Pal Benko, twin problem, helpmate in 7

Sometimes a helpmate problem, especially in a longer move setting, need not be a serious affair. There is a pretty picture in this helpmate which is a twin (a nearly identical position), the stipulation being, to remove the bishop at h4 in the last diagram. Here, also, we have a pawn promoting all the way from second rank, under-promoting, else the black king scampering to h1 would be in check. The long journey undertaken by a promoting pawn in chess problems is called Excelsior.

Pal Benko, helpmate composer

Multi-time world champion Candidate, Pal Benko, not only composed studies, but also more-movers and problems in chess helpmates. From his book with Silman, the wonderful "My life, games and compositions" comes the first of two twins. Black moving first is to help White to mate him. See the dance of the under-prmoted black rook as it races to strangle his own monarch.

A twin is a second problem with the same stipulation but a slight change in one of the pieces. Here, remove the h4 bishop from the board, and again it is a helpmate in 7 with a different solution

In Memoriam Svetozar Gligoric