(From Mat Plus No.15, Autumn 1997, p.73)
I. IntroductionThis article is concerned with one of my favorite themes from the logical school. I have two reasons to do this: First, many of the aesthetic discussions of this school are not known outside the German speaking countries. So readers have some opportunity to learn about those thoughts even if it is not possible here to report them in some depth. Secondly: In a time when formalistic aspects (those which have nothing to do with the logic of the solution: why it works) are very fashionable in chess composition I hope some will appreciate an article concerned with the quality of the moves themselves and not the pattern the moves form. In this respect the article is conservative even to the extent that many of the examples could be used to impress normal chess players without specific interest in chess problems. The English language and chess problems terminology lacks a word for one of the most fundamental stratagems. If the success of a specific attack is guaranteed by the consequences of a specific white move during the foreplan the logical school calls this white move "Führung" (German). Maybe this obvious concept was too trivial for English speaking chess problemists, and they did not introduce a term for it. So I will use the German word in this article. The logical school (and clever composers before its appearance) tried to find deep and interesting moves to be used as Führung. I only cite some of the more interesting (and therefore famous) ones: The Indian critical move, the Turton move, the Bristol (clearance) etc. Of course many white moves in a direct problem (or a game) look like Führung because White tries to advance his goals by playing them. But the logical school requires more: to try the combination leaving out that move makes some sense, but is refuted. The effects of the Führung are the only reason that after the foreplan the attack is decisive. The subject of this article is the following paradoxical theme: A specific Führung would be successful if black had not time to defend. So white allows a check, and the Führung is successful as an answer to this check. Note: In the logical school many interesting themes (like this) have not been named. Its hero is the late Dr. Hans Lepuschütz as we will see. So it is much less unjust as usual with themes named after composers to call it the Lepuschütz theme. The idea is paradoxical and can only function like this: the checking black move causes a black weakness so that after the check and the Führung Black must deal with the weakness first (often by retracting the checking move) and so has no time to do the refutation which was possible without the check. After the check and its retraction black has lost nothing but time. A sequence of moves which just loses time but does not leave other vital effects after its completion is called "Beschäftigung" in German. So we are concerned in our theme with a specific kind of Beschäftigung which makes a Führung successful. Let us look at our first (simple) example. In Nr.1 the fundamental attack (main plan) is 1.Sb3??#. The Führung (unblock of square b3) 1.Ka3!? would prepare this but 1... Be7! defends. 1.Be6! [2.Bc8:] provokes the check Be6:+ (weakening a6), but now the Führung 2.Ka3 is successful because the threat (3.Ba6) forces 2... Bc8 so that there is no time for the good move Be7 and the Führung triumphs by 3.Sb3#. To get some classification I write first the white piece doing the Führung then the black checking piece and finally the purpose of Führung. So the type of No.1 is: K/B-antiblock.
There has been much discussion whether one should only acknowledge attacks as main plans which can be played leaving out the foreplan. Here we have a very simple foreplan 1.Ka3 to allow the main plan Sb3. But the main plan 1.Sb3?? is simply impossible in the diagram. It is much better if the main plan can be really played without preparation but then is not strong enough (maybe a check is not mate because of a flight or there is some other black refutation). In this case the logic is based on something more real, namely an insufficient attack called Probespiel in German. I personally prefer much if a Probespiel exists and not only a "plan". I use the word "fundamental attack" for this attack which is not successful in the Probespiel but successful in the solution. The rest of the introduction contains most other #3 presentation of the theme I know. Nr.2: 1.Kh4? e1Q/B! 1.Sf6 [2.Sg8:] Sf6:+ 2.Kh4 Sg8 3.Sg4 Another simple example, type K/S-antiblock. The S is rare as a thematic piece.
The best #3 example is Nr.3: 1.Ke4? Bd2 1.Kd4 [2.Qc5] Bf2+ 2.Ke4! [3.Qa5] Be1 3.Qe3 This fine miniature (again type K/B-antiblock) shows that one can work without sacrifice as a first move. Nr.4: 1.Ra3? Qf2:! 1.Re3!! (Zugzwang!) Qa1+ 2.Ra3+ Qd4 3.Ra5, 1... Qh8+ 2.Re8+ 3.Rc8, (1... d5 2.Re6) The king as white theme piece is perhaps easiest to handle and therefore most frequent. Here we have the unusual type: R/Q-advance, allowing a spectacular key. The word "advance" here means that R advances to a better square from where he can mate. The reader will notice that this problem is doubling the theme. The only thing missing is a try (too slow) threatening 2.Rc8#. I would have preferred the position Rc3 to h3, +wPf5, to get that try (1.Rh8? Qf2:). Now both variations follow correct logic and we have a perfect doubling of the theme. For my taste clear logic is always worth adding a pawn, but the authors decided otherwise (not to spoil the very elegant position). Apart from some more Grasemann problems (types K/R-antiblock, R/S-advance, K/S-antiblock) these are already all the 3# presentations I can remember. (But I have no time for a thorough search in the literature so some more might exist). Most types are missing in 3 move form. Maybe the theme is difficult to introduce into more complex or more modern threemovers. One could try to triple it or present it with changed mates etc. The rest of the article will show to what tremendous depth the theme has been developed in the moremove field. II. The Lepuschütz theme as main content of a moremoverIn all of our #3 examples the Führung had a very obvious purpose. But the finer, deeper, and more unusual the purpose of the Führung the finer the problem. In this section I collect the problems with the theme as main contents. This cannot be rigidly defined because often other mechanisms and themes happen (e.g. sacrifices). So you see here the problems for which I feel the theme is central and the other things are more used to make it deeper or more spectacular. Problem Nr.5 caused a sensation when it appeared. It was the first presentation which became famous because of the theme. Solvers found the introduction 1.Ra1 Ra1:+ 2.Kb7 Rh1 unbelievable because it is difficult to spot what White has achieved by this apparently nonsense introduction. But 2 more fine sacrifices (these in fact are taken from an earlier problem by Walter Grimshaw) reveal that it is essential to guard c6: 3.Rf7+ Ke6: 4.Sd5!! Kd5: 5.Rf4#. The Probespiel for the Führung is 1.Rf7+? Ke6: 2.Sd5 Kd5: 3.Rf4+ Kc6 (demonstrates why one needs the Führung Ka6-b7). The move 1.Kb7? is not a "try" in the modern technical sense since there are several refutations. Nevertheless its existence is indispensable for demonstrating that 1.Ra1 Ra1:+ has the only reason to win a tempo. So in German we have different words for "tries not necessarily uniquely refuted but necessary for demonstrating the logic of the solution" (Probespiel) and for tries which might have nothing to do with the logic of the solution but are uniquely defeated (Verführung). (From now on I will use the more precise German word.) For the logical school an appropriate Probespiel is required. This can but need not be a try in the usual sense (normally it is preferred if it is, but this is not so important). For the ideal logical presentation of our theme we need 2 Probespiele; the first to provide a logical foundation for the Führung, the second to prove that the only reason for allowing the check is to win a tempo. This problem is so much better than the threemovers we have seen. The type is K/R-guard of a flight. I hope the reader sees from this example that it is much more important how a specific theme or type is shown that simply that is shown.
The first presentation I could find is Nr.6. 1.Ra2+? Qa2: 2.Qb4??, 1.Ke7? Qe1+ or Qe4+, 1.Bf5: Qf5:+ 2.Ke7 Qb1 3.Ra2+. Type K/Q-walk out of later pin. A nice economical position with all necessary Probespiele, but the key piece is out of play which makes the sacrifice 1.Bf5: less spectacular. Erich Zepler was a pioneer for many ideas. This is not so well known because he had the habit not to make big business out of his inventions, did not write articles about them, and left it to others to exploit them. So this first example of our theme is the only one he made. Nr.7: 1.Bg5? h2, 1.Kf3? h2!, 1.Re8 Re8:+ 2.Kf3 Kg8 3.Bg5. Same type as Nr.5 (K/R-guard of a flight) more economical but less deep.
Nr.8: 1.Bd4? Qd4:+, 1.Ka3?, 1.Rg4 [2.Rg7:] Qg4:+ 2.Ka3 Qg7 3.Bd4 Qd4: 4.f8Q. Type K/Q-walk out of later check. Nr.9: 1.Bf3? Qf8: 2.c7 Qf3:+, 1.Kh4? Qf8:!, 1.Bc8! Qb3+ 2.Kh4 Qb4+ 3.Bg4+ Qb8 4.Bf3 Qf8: 5.c7+ Qf3: 6.c8Q. Type K/Q-walk out of later check. This charming problem uses the same mate finish as the previous one. Nr.10: 1.Rc3:? dc3 2.Re4: Qe1 3.Be7+ Kc7 4.Rc4 Kb6, 1.Ka7 too slow. 1.Rh3 Qh1 2.Kb8 Qb1+ 3.Ka7 Qh1 4.Rc3: etc. Type: K/Q-guard of a flight. By the thematical introductory move and the nice moves of the black queen on the 1st row Johandl finds his own way to present the theme. Nr.11: 1.Bh2? Rh2:, 1.Ka1?, 1.Rh8 Rh8: 2.b8Q Rb8:+ 3.Ka1 Rh8 4.Bh2 Rh2: 5.Qf1:. Type: K/R-walk out of later pin. The author tried to get a deeper combination preparing the thematical check by another sacrifice. For my taste the result is only average since Rb8 and Pb7 are out of play. The basic matrix was used later more successfully (see Nr.33 and Nr.34).
Nr.12: 1.Sd3? Rd2+, 1.Ka3? too slow, 1.Kb2 [2.Qg2+ 3.Qg1+] Rb8+ 2.Ka3! [3.Qe2+] Re8 3.Sd3 [4.Qf2] Re2 4.Qh1. Type: K/R-walk out of later check. This first class miniature was derived from problem Nr.28. Therefore I believe that "after Lepuschütz" is necessary. In fact Kraemer acknowledged that the creative part had been done by Lepuschütz and had sent the problem to a paper without an own Informal tourney. But at that time there was the ring-tourney for all problems from all German papers and there he could not avoid winning a prize. Nr.13: After 1.Re5+? Kd4: 2.Qc3+ Kc3: the Re5 is pinned. To walk out of this pin by 1.Kg4? is much too slow (e.g. 1... d1Q and White can resign). Hence 1.Kf5! Qd3+ 2.Kg4 Qb5! 3.Re5+ etc. Compare this problem with Nr.5. Which is the better one? Apart from the different type (K/Q-walk out of later pin) the sacrifice in the first move has been avoided. So the key is less spectacular but perhaps more subtle. But I prefer the two sacrifices in Nr.5 to the more brutal sacrifices of the queen since one of them is without check. On the other hand the pin is more subtle than an unguarded square. In summa: The problems seem of equal (top) quality. Nr.14: 1.Ba4? Se1 2.Sd5 Bf3:!, 1.Rh8 [2.Rh4:] Rh8:+ 2.Ka7 Rh4 3.Ba4 Se1 4.Sd5 Ka2: 5.Sc3. Type K/R-walk out of later pin.
Nr.15: Hans Lepuschütz strived to hide the purpose of the foreplan. Show this position to your chess playing friend and let them try to solve it. The diagram gives no hint that White has to fear a pin and therefore it is mysterious what he achieves by 1.Rh4: Rh4:+ 2.Kg1 Rh8. Only after 3.Ra8+ Qa8: 4.Bb6 Qb8 one sees that the surprise pin on the line b8-h2 has been avoided. Type K/R-walk out of later pin. In fact there is also the Dresden theme (1.Bb6? Qc3!). Nr.16: 1.Rb1? h5 or g5, 1.Rb8 Qg1+ 2.Rb1 Qa7 3.Qh6:. Type R/Q-advance. Nr.17: 1.Rb8 [2.Qg8:+] Rc3+ 2.Kb4 Rc4+ 3.Ka5 Rc5 4.Rb5 Rc7 5.Qh6:+. Obviously this was developed from previous problem. The logic is better: A Probespiel like 1.Qh6:+? Kh6: 2.Rh3+ is absent in Nr.16 because the rook cannon rich h-line in one move. In addition the threat with another queen sacrifice is improved. For my taste this more than justifies the heavier position and the new publication. Type: R/R-white antiroman. (A move Rb5-b3 - loosing guard of g5 - forced by black, would be of Roman type).
Nr.18: 1.Re7? puts pressure on e2 but is not good enough. Loyd's problem Nr.18a shows that it would be fine to get the weaker piece in front but 1.Qe8? 2.Re7 is here too slow. 1.Ka8! [2.Rh7 3.Rh2:] Rh8+ 2.Qe8!! (now this spectacular sacrifice under check does the job! After 2... Re8:+? 3.Ka7! Black looses the control of g2) 2... Rh2 3.Re7. Black is helpless against 4.Re2:+ Be2: 5.Qe2:#. Type K/R-Loyd-Turton. This famous problem is the first connect of our theme with one of the deeper kinds of Führung, namely the Loyd-Turton move first shown in also famous pioneer which is reproduced here for reader's convenience. Nr.18a: White wants to capture Pb6 to get Qc5#. But after 1.Bf2? the queen is in the way of the bishop. The most unexpected move of all possible 1.Qg1!! solves the problem. Since 1... Kd5? is countered by 2.Qg2+ 3.Qe2# Black is helpless. After 1... any 2.Bf2 Kd5 3.Bb6: Ke5: we have 4.Qd4# (Switchback). You see Loyd not only invented his Loyd-Turton but composed a first class problem by introducing the flight d5 which makes the key almost unbelievable since there are so many attacks looking much stronger (1.Qb4?, 1.Qe4+?, 1.Qc3+?). The Loyd-Turton is much more difficult for the composer (and solver!) than the ordinary Turton where White simply clears the line backward for a stronger piece before doubling. Hence it is strange that it needed almost 20 years after Schneider before the ordinary Turton was shown in our theme! (In fact, as far as I know the simple Healey clearence - Bristol - seems to be missing until now!). Nr.19: Probespiel 1.Bg8? [2.Qe6] Rc2 or Rf2, 1.Kb7 [2.Qa8+ 3.Qa1+ 4.Qc1#] Rh7+ 2.Bf7 Rh2 3.Qe6 Rb2 4.Qa6#. If 2... Rf7:+ 3.Qf7: Kb2 4.Qf2#. 1.Bf7? (Zugzwang) is a try uniqely refuted by 1... Rf2!. It is questionable whether this try is a Probespiel since it does not threaten 2.Qe6. Nevertheless, the Turton tendency of 1.Bf7? is used after 1... Rd,g2 2.Qe6. So a finer argument would say the theme appears here as a combination of choice. Another good try is 1.Qg6? defeated only by 1... Kb2!. The construction of this problem was difficult because I naturally started with the position shifted 1 square down. But then I could not find a correct position with less than 19 pieces. Type K/R-Turton.
Erich Brunner followed a suggestion by Kohtz and Kockelkorn to show the Turton move using the same pieces. This is more subtle because one has to invent a reason for the clearance (In the normal Turton it is often obvious that one needs the stronger piece in front and the idea is not rare even in the game). Nr.20a: For reader's convenience I cite the first Brunner-Turton. 1.Rh4! Kc5: 2.Rgg4 3.Rc4, Probespiel 1.Rd4? (e.g.) Kc5: 2.Rgg4! Kc6! 3.Rc4+ Kd7. Nr.20: 1.Rcc5? Ke3: 2.Re5:+ Se4!, 1.Rb5? too slow. 1.Kb7 [2.Re5:+ Ke5: 3.Re7+ Kd6: 4.Sf5#] Rb1+ 2.Rb5 Rf1 3.Rcc5 [4.Re5:#] Sc4: 4.Rc4:#. Type K/R-Brunner-Turton. Nr.21: If Stefan Sneider showed our theme with the Loyd-clearance, why not attempt the most famous Führung moves, the Indian critical move? I tried for almost a year without success. All schemes I looked at proved hopelessly unsound (the need for stalemate is at odds with a black check and the possibility to capture the critical piece). But finally I was lucky. White wants to capture Rb3 and mate by Rd3. A well known cure for the resulting stalemate after ba3 is the Indian maneuver, here 1.Bc6?! Ra3? 2.Rd5! Rb3 3.K moves Ra,c3 4.ba3,c3. But Black has time to attack Bc6 which refutes this try: 1.Bc6? Rc3!. Strangely, capturing Bc6 is worse than attacking it from c3, as the solution shows: 1.Ke6! [2.Kf5: 3.Kg4: 4.Bf3] Rb6:+ 2.Bc6!! Rb3! (if 2... Rc6:+ 3.Kf5: Rc3 4.bc3) 3.Rd5! Ra,c3 4.ba3,c3 Kf3,e4 5.Rd3. My original position (reproduced in the FIDE-Album) was without Pf5. Then 1.Bc6? is too slow and refuted by both 1... Ra3/Rc3. As a Probespiel it is OK, but not a try in the modern technical sense. So in the book Hans+Peter+Rehm=Schach (Edition feenix Nr.3) I added bPf5 and wPg5. Later J. Kuhlmann's computer found that bPf5 is sufficient. So this is now the authorized position. By the way there is another (unthematical) try refuted only by 1... Ra3, namely 1.Bg2? Rc3? 2.Sd5+ 3.Sc3:+. Type K/R-critical move.
Nr.22: After 1.Sf6? Bh3: White would like to play a Novotny by Rf7-f5, but he has interfered his rook. So an anticritical move is wanted. 1.Rf1..4? is too slow, hence our theme 1.Kb2 [2.Bd7+ 3.Sf6+ 4.Bb5] ba3+ 2.Kb3 [3.Bd7+ 4.Sf6#] Rh3:+ 3.Rf3! Rh5! 4.Sf6 Bh3 5.Rf5. Type K/R-anticritical move. III. Doubling the themeDoublings of the theme are very rare (in parallel variations as well as in one variation). I believe a lot could be done in this (admittedly difficult) field. The next Nr.23 is an extension of Nr.4 to 4 moves, but I believe this is well justified by the finer play with dual avoidance. 1,Rf4?, 1.Rf3? too slow. 1.Rf7 Qh6+ 2.Rf4+ Re6 3.Sf6+(Sc3+?) Sf6: 4.Qc4# 1... Qh3+ 2.Rf3+ Qe6 3.Sc3+(Sf6+?) 4.Qe4# 1... cb5:/Sg7/Rb4/c4 2.Qa8+/Sf6+/Sc3+/Qa8. Type R/Q-closing of black line + R/Q-advance. The type "closing of black line" is only in this (and the next) problem. I felt that the construction should be improved.
Nr.24: 1.Sf3+? Bf3: 2.Qd4+ Sd4:, 1.Rc3? too slow as is 1.Rd3? 1.Rg3 [2.Rg5+ hg5 3.Qg5: 4.Bf4:] Qc1+ 2.Rc3 Qf4 3.Sf3+ (Sc6+?) Bf3:,ef3+ 4.Qd4# 1... Qf1+ 2.Rd3+ Qf4 3.Sc6+(Sf3+? ef3+!) Sc6: 4.Rd5. Type R/Q-closing of black line + R/Q-advance. Nr.25: 1,Kb3? too slow, 1.Kc3 Ba5+ 2.Kb3 Bd8 3.gh3! [thr.(f5) 4.Bf1 Ke4 5.Se5 f4 6.Bg2+] f6! 4.Kc3(4.Kc2?) Ba5+ 5.Kc2 Bd8 6.e4+ Kd4: 7.Se6. In order to get a threat forcing f7-f6 we need an additional guard on c4; having forced f6 the guard of d3 has to be restored. Both is done with the thematical manoeuvre. Type K/B-guard of a flight square + K/B-guard of a flight square. The elegant mechanism was also used in collaboration with my friend Stephan Eisert. Nr.26: Instead of nice model mates we tried to make deeper reasons for doing the thematical pendulum. Who would suspect in the diagram that the position of Kf6 is bad because the diagonal h8-d4 is closed? But 1.ab6? is refuted only by 1... Bf2!! 2.b7 Be3: 3.b8Q Bd2:, which without Kf6 could be answered by 4.Qh8:+ Kd5 5.Qe5#. So 1.Ke6 Bc8+ 2.Ke7 Ba6 3.ab6 [4.Sf5+ Kd5 5.Rc5#] cb6 (not Bf2?). The Probespiel of Führung Ke7-f6 back is now 4.b5? cb5? 5.Ke6, but 4... Sg6+ Bg6: cb5, and 6.Ke6 is not strong enough since Sf5 closes the bishop's line. (Black forced the critical move Bb1:g6). But after 4.Ke6 Bc8+ 5.Kf6 Ba6 6.b5 Black has only 6... cb5 7.Ke6 Bc8+ 8.Rc8: 9.Sf5#. By walking out of the line White walks into a check which allows Black to force a critical move. Type K/B-line opening + K/B-walk out of check. Nr.27: 1.g4? h1Q!, 1.Kd6 Bf8+ 2.Kd7! [3.Rf4+] Bh6 3.g4 [4.Sf2+] h1S 4.Kd6 Bf8+ 5.Kc6 Bh6 6.Sc5+ Ke5: 7.Rf5. Here our aim was to make the king's pendulum less obvious because now it grants a flight (d5). Type K/B-walk out of pin + K/B-guard of flight square. At first sight Kc6-d7 is done to guard e6. But this is not correct thinking because it would not be necessary to control e6: after 1.g4? we need no guard on e6 by the white king (threat 2.Sc5:+). The guard only compensates the loss of control of c,d5. Thus White is forced to exchange his threat 2.Sc5: for the weaker one on f2 for which there is a direct defence h1S. By the switchback the stronger threat is restored. From these examples the reader may learn that the same basic mechanism leads to rather different problems if the logic for doing things is different.
I cannot resist to cite here a wonderful problem which is not strictly thematical, but close to the spirit of the theme. Nr.28: 1.Bb8? Rc3: or cb3 (Probespiel, not try!), 1.c4? again too slow (b1Q or Se2). We need a lot of Beschäftigung before these moves become strong enough. 1.Se6 Bf2+ 2.Sc5 Bg3 3.Sd7 Bf2+ 4.Sb6 Bg3 5.c4! Bc4: (now forced because of the threat 5.Sd5: Bf2+ 6.Se3 Be3: 7.Ka8 8.g4#) 6.Sd7 Bf2+ 7.Sc5 Bg3 8.Se6 Bf2+ 9.Sd4 Bg3 10.Kb8 b1Q 11.Se6 12.Sf4+ 13.g4#. A lot of moving around after checks causing a weakness. The only thing "missing" is that the Probespiel for the Führung is absent (playing the move without check). But this is more by chance. If the knight d4 would have power to do the moves 1.Sd4-c5, Sc5-b6 etc (say S+fers) the problem would present our theme correctly 4-fold. Some will perhaps suggest not to ask for the Probespiel of the Führung in our theme. But then the theme becomes less clear-cut: problems where a white king runs away (being constantly checked) would be thematical if one of the checks causes a weakness in black's position. IV. Combining the theme with other ideasNr.29: In this beautiful early example a Roman follows our theme: 1.Sa6? Rd7, 1.Kh6? too slow. 1.Kg7 [2.Qb7+ 3.Qb8+] Rg4+ 2.Kh6 Rd4. Now 3.Sa6? Rd7 4.?. Wee need the rook to block b7, hence: 3.Rb4: Rb4: (Roman decoy) 4.Sa6 Rb7 5.Qe8. The type is: K/R-unpin. Nr.30: 1.Rc2? d3, 1.Se5:+? Be5: 2.Rc2 g6+!! 3.Kg8 e3. 1.Ra8 Ra8:+ 2.Kh7 Ra4 3.Se5: Be5: 4.Rc2 e3 5.Qf5#. Type: K/R-walk out of (later) check. The theme is combined with a black decoy opening the line Df2-f5. This fine composition has a very subtle black check g6+: first g6+ is deep because it is not obvious in the diagram: white only makes it possible when he forces the necessary line opening; secondly, this check by Be5 is only good because it wins a tempo to guard f5. White wins a tempo by allowing a check in order to prevent black to win a tempo by checking. One admires that such a deep idea has been realized in such a wonderful light position.
Nr.31: 1.Ka5 [2.Sd7:+ 3.Sf6+ 4.Se4+ 5.Sc3+ Kc6 6.Qc8] Bb6+ 2.Kb5! Rb2+ 3.Ka4 Re2 4.Sd7:+ Kd5 5.Qc4+ Kc4: 6.Sb6. Type K/R-walk out of check. The theme begins after 1.Ka5 [2.Sd7:+ 3.Sf6+ 4.Se4+ 5.Sc3+ Kc6 6.Qc8] Bb6+ (decoy, wakening b6) 2.Ka4? is too slow for black can for example retract his decoy (2... Bb6-g1). Hence 2.Kb5! Rb2+ 3.Ka4 Re2 and now the main plan 5.Sd7:+ Kd5 5.Qc4+ Kc4: 6.Sb6:# succeeds. The correctness of this position with the strong queen and Siers battery must have been very difficult to achieve in a time when computers were barely invented and everybody believed that a machine playing chess or testing problems would be impossible. The logic of this problem is unique: A Führung (here Ka4-a5) is not interesting in itself but used "only" to force a black decoy. But it weakens also the white fundamental attack (here by putting the wK into check, but other motives would be also very welcome) such that has to be taken back. But if White takes it back (Probespiel of the thematical Führung) Black also takes back his decoy. That's why our theme is called for. Writing this article I thought it would be very nice to have more presentations of this logic. In fact, I wrote a short article about this question in "Die Schwalbe", feb. 1997 (Eine seltene logische Kombination). Nr.32: The Probespiel 1.Sg6+? Rg6: 2.Bf4+ Kf5 3.Bd7+ Bd7: shows that White would prefer the black bishop on h3. This is readily achieved by 1.Bd1 [2.Rf5+ Kf5: 3.Bg4+ Ke5 4.f4#], but the white bishop i also away from d7. If White takes back this move (2.Ba4?) Black can do the same (2... Bc8! or Be6!). That is why our theme is now needed: 2.Ra7: [3.Re7+ or 3.Rg7:] Ra7:+ 4.Ba4! Rg7! (not Ra4:+? 4.Kb1 5.Sg6 or Sf7) and we have what we want (4.Sg6+ Rg6: 5.Bf4+ Kf5 6.Bd7#). If 1... d2 then after 2.Bd2: [3.Rae3+ 4.Bc3] Sb3 the threat is enough (3.Rf4+ etc.). Type K/R-retraction of partially bad move.
Nr.33: In this composition the theme is combined with the Dresden theme which is apparent already in the Probespiel: The good defence (1.Qc7?) Rb1 is replaced after 1.Bb5? ab5 2.Qc7 by the worse 2... Ra7:. But the pin hinders white to use the block on a7. So, in addition, our theme - type K/R-walk out of (later) pin - is necessary: 1.Kg8? too slow, 1.Rh2 [2.Rd2:] Rh2:+ 2.Kg8! Rd2 3.Bb5 ab5 4.Qc7 Ra7: 5.Qc8. The same finale is used in the next problem to combine our theme with a pendulum manoeuvre. Nr.34: One can try to move the king at once to avoid the later pin (1.Ba7? Ra7: 2.Qc8??): 1.Kd6? too slow. A la Lepuschütz 1.Kc6? Rc1+ 2.Kd6 Ra1 3.Ba7 would be very good, but 2... Rc7: destroys White's dreams. So a preparation is necessary to get Kc6-d6 sound. 1.Qc8 [2.Bc7+ 3.Qb8+] Rb1 2.Bc7+ Ka7 3.Kc6 Rc1+ (3.Kd6? too slow) 4.Kd6! Rb1! and returning to the original position finishes the job: 5.Bb8+ Ka8 6.Qc7 Ra1 7.Ba7 Ra7: 8.Qc8. Type K/R-walk out of pin. A pendulum in order to shield a piece (here white queen) is very unusual. Only a master of the logical school can have thought to combine this with our theme. Such a deep idea has been realized in an incredibly economical position.
Nr.35: 1.Sba5? Ra5: 2.Ba4 Ra4: 3.Kd1 Rc4:, 1.Kd3:? too slow. 1.Ke3 Re7+ 2.Kd3: Sb4+! 3.Kd2 Ra7 4.Sba5 Ra5: 5.Ba4 Ra4: 6.Kd1 7.Sd2. Type K/R-capture. The theme is marginal here but unusual is that not the Führung Kd3: is the final aim, but the move Sb4 which is forced by the threat on c2. The guarding duty is transformed from Pd3 to Sb4 which closes the line a4-c4. Nr.36: 1.Se2? g5 2.Sc3 f6 3.Se4 stalemate. The theme is here executed using Indian unpinning of the black thematical piece: 1.Bd1! g6! 2.Se2 Rc4:+ 3.Sc3+ Rg4 4.Se4 g5 5.Sf6:, 2... g5 3.Kb1 f6 4.Ka1!!. A strange form of the theme: White does not win a tempo but Black loses time such that he cannot prepare his stalemate. Type R/S-black loses a stalemate. By the way, this position is a good argument against those who contend the purpose of the Indian critical move is to avoid stalemate. I hope the reader has seen from this article that in the logical school, even in just one theme, a lot remains to be done. For our theme most of the types are missing! And many types have been shown only once and only one matrix has been explored (in which other field of chess composition is a similar statement nowadays correct?). There are, of course, reasons for the missing types. The wP as a thematical piece is perhaps absent because schemes for it look too easy and trivial at first sight. But it is not forbidden to invent a wonderful problem using the pawn thematically. Doublings of the theme are very rare. In single presentations (only one variation) one can try to follow Lepuschütz and make deeper combinations. Promising is the idea to hide the theme more by adding a foreplan such that the possibility to allow the black check appears only after the foreplan. I recommend especially what has been said to Grasemann's Nr.31 for further study. |