BPCF 2019 - XIV Београдски фестивал проблемског шаха 2019.
Belgrade Internet Tournaments 2019
Group A – #2 , Mate in two moves
Judge:
Dr. Paz Einat, International Judge
Director:
Marko Ložajić
It was an interesting idea by Marjan Kovačević to use the 4-phase reciprocal changes theme, which I promoted
in the last couple of years, as a theme for this year’s Belgrade Internet Tourney. My hunch was that much can be
done, but only after receiving the 17 anonymous problems from the director, Marko Ložajić, I could see that my hunch
was correct.
The problems presented a good variety of mechanisms realizing the theme. My clear preference was for mechanisms that
are purely 4-phase ones. One problem had a 2-phase mechanism and two others had 3-phase mechanisms, in both cases
somewhat artificially spread onto four phases. Such adaptation should not be dismissed, they can be of interest,
but I gave them lower preference.
The 4-phase requirement gave rise to mechanisms based solely on separation of defenses by the threats. This means that
both defenses would give rise to the same thematic mate but the threats determine that only one is a real defense.
Such mechanisms has a definite taste of artificiality, but in some way, they might look rather humoristic. I gave
these the lowest preference but I did not dismiss them altogether.
Now to the award. Grading the problems was not an easy task and the differences between the problems were small.
In addition to the thematic requirement, I used a variety of criteria and tried to weigh clarity versus complexity and
the importance of additional element.
Thematic condition
4-phase reciprocal changes
Reciprocal changes of two mates, spread over 4 phases, according to the pattern presented in the examples.
Example 1
Paz EINAT
3rd HM, The Problemist 2017
#2
(12+11)
Example 2
Paz EINAT
1st Pr. Israel QCT 2017
#2
(10+8)
Example 3
Мarjan Kovačević
3rd Pr. Die Schwalbe 1983
#2
(7+8)
Winners
Anatoly Vasilenko
Mark Basisty
Vasil Markovcij
Mihail Hramtsevich
Dragan Stojnić
Participants
Mark Basisty – UKR (1,7*)
Hubert Gockel – GER (2,8)
Mihail Hramtsevich – BLR (4*,9*)
Zoltán Labai – HUN (3*)
Vasil Markovcij – UKR (4*,9*)
Miodrag Mladenović – SRB (11)
Pavel Murashev – RUS (5,10)
CGS Narayanan – IND (12,16)
Vyacheslav Pilchenko – RUS (6*,13*)
Valery Shanshin – RUS (6*,13*)
Dragan Stojnić – SRB (14,17)
Gábor Tar – HUN (3*)
Anatoly Vasilenko – UKR (7*)
Daniel Wirajaya – INA (15)
14 names
from 8 countries
BPCF2019A - Award
Set: 1...d4 2.??
1.Qf3? zz 1...d4 a 2.Sb7# A
1...d2 2.Qc3# 1...R~ 2.Bd4# 1...b4 2.axb4# but: 1...f6!
1.Se3? [2.Qxd5#] 1...Rg5 b 2.b4# B
(1...Kd4 2.Qxd5#) but: 1...f5!
1.Qxf7? zz 1...d4 a 2.b4# B
1...R~ 2.Bd4# 1...b4 2.axb4# but: 1...d2!
1.Se7! [2.Qxd5#] 1...Rg5 b 2.Sb7# A
1...f5 2.Se6# (1...Kd4 2.Qxd5#)
(1.Qd1? [2.Qc1#] 1...d2 2.Qc2# 1...Rg1 2.Bd4# but: 1...d4!)
A very clear 4-phase mechanism. In two phases, we have line opening by BPd5 once to c6 and once to c4, enabling, alternatively, the Sb7 & b4 mates. In the other two phases, we have flight provision on d4 by the keys, which guard either c6 or c4. Thus, the line opening by the BR-defense, guarding the d4 flight, enable the same two mates. In these two phases, one can argue that 1...d4 would also self-block on d4 and enable the mates (it is prevented by the pin), but this is incidental and not part of the mechanism. Good additional mate changes and the use of both waiting and threats shows the flexibility of the composers.
FEN: 3N3B/2p2pr1/2Pp4/Kpkp1N1Q/5P2/PP1p3P/1P3P2/8
(C+ by Popeye)
1.Rh4? zz 1...S~ a 2.Bxf4# A, but: 1...Kxd6!
1.Qa5? zz 1...S~ a 2.Qxc5# 1...Kxd6 b 2.Sxc4# B
but: 1...Sb4!
1.Qb1? zz 1...S~ a 2.Sxc4# B 1...Kxd6 b 2.Qb8#
but: 1...Sb2!
1.Qd1! zz 1...S~ a 2.Re7# 1...Kxd6 b 2.Bxf4# A
The 4-phase reciprocal changes mechanism is not as clear as in the 1st Prize problem, but there is a 3x2 Zagoruiko involving the thematic defenses. Both Sxc5 & Bxf4 mates can be given after 1...Kxd6 provided that the right squares are guarded and (for Bxf4) that BSd3 is pinned. For the mates after the 1...S~ defense, Sxc5# requires guard of f5 and Bxf4# guard of f4. The three try and key moves provide these to drive the reciprocal changes. The refutations of the 2nd & 3rd tries are excellent, and the way the composer managed the additional mates completing the Zagoruiko is admirable.
FEN: 8/K2p3R/2pP1p2/2p1kP2/2p2n2/2PnN3/6BB/Q7
(C+ by Popeye)
Set: 1...S~ 2.Bxf5#, 1...Se5! (2.Bf5?)
1.Sexd4? [2.Qf3#] 1...Qxd5 a 2.Qe3# A
1...Se5 2.Bxf5# but: 1...Rf4!
1.Sbc7? [2.Qd3#] 1...Rxd5 b 2.Qxd5# B
1...Se5 2.Rxd4# 1...Sf4 2.Bxf5# but: 1...Ba6!
1.Sec7? [2.Qd3#] 1...Qxd5 a 2.Qxd5# B
1...Se5 2.Rxd4# 1...Sf4 2.Bxf5# but: 1...Rg5!
1.Sbxd4! [2.Qf3#] 1...Rxd5 b 2.Qe3# A
1...Se5 2.Bxf5# 1...Rf4 2.Sg5#
(1.Bf4? [2.Rxd4#] 1...d3 2.Qxd3# 1...Sxf4 2.Bxf5#
1...Rxf4 2.Sg5# but: 1...Qxf6!)
The two black lines mechanism, first shown by one of my problems, is adapted here in a very nice and different way. The 1st moves by the WS’s either guard d5, and enable the mate on d5, or capture d4 and enable the self-block on d5 to be exploited by the Qd3 mate. Nice and clear! The composer neatly used the matrix to devise two different refutations on the tries on c7 and the additional Dombrovskis element, with the mate change on 1...Se5, is a good addition
FEN: 8/1b2pq1B/1pP1NPnB/rN1R1p2/1p1pk1rp/pQ4p1/2P5/2K5
(C+ by Popeye)
1.Qd1? zz
1...Kxd6 a 2.Bf4# A 1...S~ b 2.Qd5#
1...Sf4 2.exf4# but 1...Sb4!
1.Qb1? zz
1...Kxd6 a 2.Qb8# 1...S~ b 2.Sc8# B, but 1...Sf4!
1.Qa5? zz
1...Kxd6 a 2.Sc8# B 1...S~ b 2.Qxc5#, but 1...Sb4!, Sf4!
1.Rf8! zz 1...Kxd6 a 2.Sb5# 1...S~ b 2.Bf4# A
The ideal way of showing the 4-phase reciprocal changes in the format of a 4x2 Zagoruiko. This problem, which is a version of the 2nd Prize by the same author, incredibly achieved this task! The price paid are two refutations on the 1.Qa5? try. One can regard this as “refutation separation”, as the next two tries have these refutations individually, but I see it as a weakness. Also, WBa8 is unused in the solution. The mechanism is different enough for the problem to stand on its own, in principle due to the use of the WQ/WS & WR/WS batteries.
FEN: B3R3/K3N3/2PP4/2p1kPB1/2p5/2NnP3/8/Q7
(C+ by Popeye)
1.Bg3? zz 1...e4 a 2.Rh5# A
but 1...exd4 b !
1.Kb7? zz 1...exd4 b 2.Qa2# B, but 1...e4 aa !
1.Bf2? [2.e4#] 1...e4 a 2.Qa2# B, but 1...exd4!
1.Rf6! zz
1...exd4 b 2.Rh5# A 1...e4 a 2.Rf5#
(1.g7? zz 1...exd4 2.e4# but 1...e4!)
The problem probably shows the most original mechanism. The moves by BPe5 both guard e4 and open the 5th row. However, 1...e4 prevents both thematic mates due to the unpin of BRg2, and 1...exd4 prevent them by unguarding c6 and e6. The tries and key either make an interference of the BR lines or guard c6 & e6 (separately). The mate change on 1...e4 in the solution is good but the repetition of the refutation is a weakness
FEN: K7/2p5/2PpR1PR/3kp3/pP1N4/P3P2p/2Q3rp/4B2B
(C+ by Popeye)
(1.Se7? [2.Sc6#] 1...Sb8 2.Qd4# 1...Qxc2 2.Rxe3#, but 1...Qh1!)
1.Rxg4? [2.Bxf4#] 1...Bxh2 a 2.Qe4# A
1...Bg3 2.Qe4# 1...exf5 2.Re8# but 1...Qf1!
1.Sxe3? [2.Sc4#] 1...Sb6 b 2.Qd4# B
1...Bxe3 2.Rxe3# 1...Qxe3 2.Rxe3# but 1...Qxc2!
1.Rf3? [2.Bxf4#] 1...Bxh2 a 2.Qd4# B
1...Bg3 2.Qd4# 1...exf5 2.Re8# but 1...g3!
1.Sd6! [2.Sc4#] 1...Sb6 b 2.Qe4# A
1...Qxc2 2.Rxe3#
The mechanism is from the same type as that of the 1st Prize but with a twist. The tries by the WR open guard on f5 or e4 after the BB defense, leading to the thematic mates. In the 3rd try WSf5 provides guard on f5 alone, enabling the Qd4 mate after the defense by BSd7, while the solution provides guards on both f5 & e4 but closes the d-file for the WR thus preventing the guard on d4 by the defense move.
FEN: 3R4/3n2p1/4p1Pn/1K2kN1N/5bpp/1p1Qp1R1/2P1p2B/2q5
(C+ by Popeye)
1.Sf3? [2.Se1#] 1...Rxe4 a 2.Bxe4# A
1...Bf2 2.Qd1# but 1...g2!
1.Sd5? [2.Sb4#] 1...Qxe4 b 2.Qxe4# B
1...Bc5 2.Qd1# but 1...c5!
1.Sc6? [2.Sb4#] 1...Rxe4 a 2.Qxe4# B
1...Bc5 2.Qd1# but 1...Rb5
1.Sg2! [2.Se1#] 1...Qxe4 b 2.Bxe4# A
1...Bf2 2.Qd1#
(1.Sfd3? [2.Se1,Sb4#] but 1...Qxe4!
1.Sed3? [2.Se1,Sb4#] but 1...Rxe4!)
Another way to express the two black lines mechanism (see 3rd Prize). The moves by the WS’s either close the WQ or WB while opening the BQ or BR lines. Therefore, these are a kind of bi-color valve moves. The board geometry is nicely used for the WS threats, the additional tries on d3 feature the thematic defenses as refutations, and the refutations on the thematic tries are all fine.
FEN: B7/2p1r3/8/4N1r1/4PN1q/p1B3pn/KpkP4/nR4bQ
(C+ by Popeye)
1...fxe5 a 2.Qg6# A
1.Sxe3? zz 1...fxe5 a 2.Qg6# A
but 1...f5!
1.Rd5? zz 1...fxe5 a 2.Qxe5# B
1...Kxd5 2.Bxf7# 1...Kf5 2.Qh3# but 1...f5!
1.Bd4? zz 1...f5 b 2.Qe5# B
1...Kd5 2.Bxf7# 1...cxd4 2.Sxd4# but 1...Kf5!
1.Bf4! zz 1...f5 b 2.Qg6# A
1...Kf5 2.Sd4#
A very nice mechanism, using the set play as one of the phases. The WQ will mate on g6 or e5 (if free and guarded) following defenses by BPf6. Determinants are the flight on d5 and blocking the WQ towards e5. It would have been nice to have the flight-giving 1.Bd4? try as the solution. Overall, there are additional mate changes and a mate transfer.
FEN: 1N4B1/5p2/1p1Pkp1K/1Rp1B3/2p1p3/2P1p1Q1/2N1P3/3R4
(C+ by Popeye)
Set: 1...Bd4+ 2.Sxd4# 1...c3 2.Qf1#
1.Qb1? [2.Qf1#] 1...Be5 a 2.Rf4# A
1...Bd4+ 2.Sxd4# 1...Bxe4 2.Qxe4# but 1...Sc1!
1.f8=Q? [2.Sd4#] 1...g4 b 2.Re5# B but 1...Bxe4!
1.Qxc4? [2.Qf1#] 1...Be5 a 2.Rxe5# B
1...Bd4+ 2.Sxd4# 1...Bxe4 2.Qxe4# but 1...Ba6!
1.Qd7! [2.Sd4#] 1...g4 b 2.Rf4# A
The basic mechanism is well known from the 2-phase reciprocal changes (WQ on b1 for double check-mates on guarded squares and WQ on e2, guarding e6 & g4, with mates on unguarded squares). However, the use of the pinning try nicely takes this into the 4-phase realm.
FEN: 1B6/1b2pPP1/4Nb1R/1QK2kp1/2p1R3/8/n5B1/8
(C+ by Popeye)
Set: 1...Kxe4 a 2.Sxg3# A
1. Sc4? [2.Re5#] 1...Kxe4 a 2.Qxd5# 1...Qxe4 b 2.Sxd4# B
but 1...Re8, dxe4!
1. Sg4? [2.Re5#] 1...Qxe4 b 2.Sxg3# A
1...Re8 2.Qh7# but 1...dxe4, Kxe4!
1.Sf3! [2.Re5#]
1...Kxe4 a 2.Sexd4# B
1...Qxe4(/dxe4) b 2.Sh4# 1...Re8 2.Sxg3#
1. Sg6? [2.Re5#] 1...dxe4 2.Sh4#
(1...Qxe4 2.Sxg3, Sh4#) but 1...Kxe4, Re8!
The low place of this problem is due to the presence of two refutation in all tries. Other than this, the problem is rich in content and presents a pleasing mechanism. BK defense on e4 can lead to Sxg3 or Sxd4 depending on the need to guard f3 and the availability of a guard on d4. BQ capture on e4 leads to these mates depending on which of these squares were unguarded by interferences by WSe5. There is a 3x2 Zagoruiko plus additional changes, the defenses on the same square are nice and tries and key are by the same WS. Counting the non-thematic 1.Sg6 try, the double refutations show cyclicality, but this fact does not reduce the weakness inherent in them.
FEN: 3b2r1/2pP1Q2/2K2P1B/1pPpNk2/1r1pRP2/3q2pP/b3N3/1B2R3
(C+ by Popeye)
Set: 1...cxd4 a 2.R5xd4# A 1...fxe5 b 2.Rxe5# B
1.Rd3? [2.Re3#] 1...cxd4 a 2.R5xd4# A
1...Sxd5 2.Qf5# 1...Sf5 2.Qxf5# 1...Bxd3 2.cxd3# but 1...Rxd5!
1.Qh2? [2.Qf4#] 1...fxe5 b 2.Rxe5# B
1...Sh3 2.Qxe2# but 1...Sg6!
1.Sd3? [2.Sf2#] 1...cxd4 a 2.Re5# B
1...Bxd3 2.cxd3# but 1...Sh3!
1.Sf5! [2.Sg3#] 1...fxe5 b 2.R5d4# A
1...Sxf5 2.Qxf5#
This is, in principle, a 3-phase reciprocal changes problem since the captures, when both WS’s are on d4 & e5, can be done in one phase, and they exist as set play. Still, the WS try and solution are fine and the use of four different threats and three unique refutations make this a good composition.
FEN: B2r3b/4n3/1q3p1B/2pRN2Q/1pPNk1P1/2p5/2P1b3/2KR2n1
(C+ by Popeye)
1.a8=Q? zz 1...Kd5 a 2.Rd2# A
1...Kxf3 2.c7# 1...Kd3 2.f6# but 1...gxf3 b !
1.Be3? zz 1...gxf3 b 2.Rc5# B
1...Kd3 2.f6# 1...Kxf3 2.Qh1# but 1...Kd5 a !
1.Bf8? zz 1...Kd5 a 2.Rc5# B
1...Kd3 2.f6# 1...Kxf3 2.Qh1# but 1...gxf3 b !
1.Bf4! zz 1...gxf3 b 2.Rd2# A 1...Kd5 a 2.Rc5# B
1...Kd3 2.f6# 1...Kxf3 2.Qh1#
Another 3-phase mechanism extended into four. Here, both thematic variations exist in the solution (1...Kd5 a 2.Rc5# B 1...gxf3 b 2.Rd2# A) and together with the tries 1.a8=Q? and 1.Be3? we have 3-phase reciprocal changes. The additional phase does fulfil the required pattern and there are additional mate changes.
FEN: 8/P4K1Q/2P4B/5P2/1P2k1p1/1P3NP1/2R2P2/1B6
(C+ by Popeye)
1.Sh6? [2.Qf5#] 1...Sxd6 a 2.Scxd6# A
1...Bg6 2.Qxf3# but 1...Bg4!
1.Scxe5? [2.Rd4#] 1...Rxd6 b 2.Sfxd6# B
1...Bxe5 2.Qxe5# 1...Rxf2 2.Sxg5# but 1...Sxc3!
1.Se3? [2.Qf5#] 1...Sxd6 a 2.Sfxd6# B
1...Bg4 2.Sxg5# but 1...Bg6!
1.Sfxe5! [2.Rd4#] 1...Rxd6 b 2.Scxd6# A
1...Sxc3 2.Sd2# 1...Bxe5 2.Qxe5#
This and the next two problems have mechanisms based on white threats. Here, a capture by both BRc6 and BSb7 on d6 leads to mates by both WS’s on d6 due to the half-pin. The separation elements involve the WS tries and key and the different threat that determine if the defense will be by the BR or BS. This is of course very artificial, and we do not really have reciprocal changes, but I find the ability to show the pattern in this way rather humoristic.
FEN: B7/1n1p1NK1/2rP1Q2/2P1p1pb/2N1k3/2PR1p2/2P2Prb/1n6
(C+ by Popeye)
1.Sf3? [2.Rg5#] 1...gxf6 a 2.Qg4# A
1...Rg1 2.Sxh4# but 1...exf2!
1.c8=S? [2.Sxd6#] 1...Rxf6 b 2.Qe4# B
but 1...Ba3!
1.f4? [2.Rg5#] 1...gxf6 a 2.Qe4# B
but 1...Rg1!
1.Sc4! [2.Sxd6#] 1...Rxf6 b 2.Qg4# A
1...Ba3 2.Sxe3#
(1.Rg4? [2.Qf4#] but 1...g5!
1.fxe3? [2.Qf4#] 1...g5 2.Rf2# but 1...Rf1!)
The tries and key leave one possible WQ mate following the self-block on f6. However, this mate can be given on both defenses and it is the threat that “prevents” one of them from being relevant.
FEN: 4brn1/2Pp2p1/3p1P2/3P1k1P/K2Q3p/4p3/3NpPR1/2b4r
(C+ by Popeye)
1.Kf7! [2.Qh8#] 1...Rf3+ a 2.Sf5# A
1.Qd7! [2.Qxa7#] 1...Rxb3 bB
1.Kd7! [2.Qh8#] 1...Rf3 a 2.Sxb5# B
1.Qa5! [2.Qxa7#] 1...Rxb3 bA
1...a6 2.Qb6#
As above, only one of the defenses works due to the threats. In two phases the battery remains and the double-check mate on the guarded squares is forced in different ways. In the other two phases the battery is inactivated and the mate can be given only on the unguarded squares. Using a 4-solutions approach is a simplification that I do not favor.
FEN: 3QK3/p3P2p/2RN4/1p6/2pkP1N1/1R1r4/8/1B3b2
(C+ by Popeye)
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