Petko A. Petkov


Original Problems, Julia’s Fairies – 2015 (II): July – December

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Please send your original fairy problems to: julia@juliasfairies.com

roses-100No.895 by Petko Petkov – A very nice threefold cyclic play of Chinese pieces PAO, NAO, RAO! I’m so grateful for the dedication! (JV)


Sentinels: When a piece (Ks included but not pawns) moves, a pawn of the same colour appears on the vacated square unless that square is on the first or eighth ranks or there are 8 pawns of that colour on the board already.

Anti-Andernach: A piece (excluding King) changes its color after any non-capturing move. After capture, the piece retains its color. Rooks on a1, h1, a8 and h8 can be used for castling, provided the usual other rules for that move are satisfied. After castling, Rooks do not change color. If White makes a non-capturing move with neutral or halfneutral piece, that piece becomes black and vice versa.

NAO(NA): Chinese piece operating along the lines of Nightrider: moves as Nightrider, but captures only by hopping over a hurdle to any square beyond.

PAO(PA): Chinese piece operating along Rook lines: moves as Rook, but captures only by hopping over a hurdle to any square beyond.

RAO(RA): Chinese piece operating along Rose lines: moves as Rose, but captures only by hopping over a hurdle to any square beyond.

Nightrider(N): Operates along straight lines with squares lying a Knight`s move away from each other.

Rose(RO): (1,2) Octagonal Rider (extents the move of the Knight on a circular path e.g. a4-b6-d7-f6-g4-f2-d1-b2 or a4-c5-e4-f2).

No.895 Petko A. Petkov

original – 16.09.2015
Dedicated to Julia in her birthday!

Solutions: (click to show/hide)

white ke5 Qe8 paf4h6 pd5e3 black kg1 paa6 sc2 raa3 nac8 pf2

hs#3                                         (6+6)
b) Qe8→d7; c) +black Pg3
NAO c8; RAO a3
PAO a6, f4, h6

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September 16, 2015 14:44

Very nice problem! Happy birthday Julia!

Kenneth Solja
Kenneth Solja
September 16, 2015 17:50

I was wondering why there is black knight in c2 which isn’t doing nothing, so I tried the position with black in c5.
Both pieces are only guarding d4 square.

White Ke5 Qe8 PAh6 PAf4 Pd5 Pe3
Black Kg1 RAa3 NAc8 PAa6 Pc5 Pf2
HS#3, Sentinelles, Anti-Andernach
A) diagram B) Qe8->d7 C) +black Pg3
C+ with Popeye 4.73

A) 1.Qg6=b PAf6=w[+bPa6] 2.PAd6=b[+wPf6] Qh5=w[+bPg6] 3.Qxg6[+wPh5] + PAxg6[+bPd6]#
B) 1.Qh3=b[+wPd7] NAe4=w 2.NAd6=b[+wPe4] Qf3=w[+bPh3] 3.Qxf2[+wPf3] + NAxf2[+bPd6]#
C) 1.Qd8=b RAf5=w[+bPa3] 2.RAd6=b[+wPf5] Qh4=w 3.Qxg3[+wPh4] + RAxg3[+bPd6] #

The solutions are the same, so I hope Petko would explain why he uses black Knight instead of black pawn? I’m not saying this is better and perhaps there is something I’m not seeing..

Happy birthday Julia !

Kenneth Solja
Kenneth Solja
September 16, 2015 17:51

I like the problem itself.. It is really good..

shankar ram
shankar ram
September 16, 2015 18:34

The Nao/Rao bug strikes again! Both having the same piece symbol in the diagram… 😉

petko petkov
petko petkov
September 16, 2015 18:55

Dear Kennet,

The black Sc2 is needed because it closes the RAO line via direction c2-e3-f5. Therefore without Sc2 (or an other piece, for example Pawn in c2) in solutions a) and b) the black RAO controls square f5 in two ways – via b5-d6 f5 and via c3-e3-f5. Such needless “dual control ” of the field using a piece of the Rose family is very objectionable at all! I also believe that in such cases there is no model mate because f5 is attacked twice by a black RAOa3 !

Juraj Lörinc
September 16, 2015 22:10
Reply to  petko petkov

I think it is important to distinguish.

In this specific problem, the choice to shut off “line” c2-e3-f5 is in my view undoubtedly correct – the mechanism includes as an important part activation of black Chinese lines on d6. Additional guard existing in the diagram position would ruin the unity.

However, the purity of checkmate would not be affected. If only one piece guards one unblocked specific square using two lines, it is still pure. While this might be arguable, the fact is that even old Bohemian masters who were composing on cylindric board (e.g. Mandler, Mach) were considering as pure guarding of square by rook or bishop using different directions around the cylinder. In this sense I am also considering problems competing in the 148th TT SuperProblem.

Luce Sebastien
Luce Sebastien
September 16, 2015 21:07

Sorry but n°895 is insoluble Winchloe.

(for info Julia, I register alone all the problems of Julias Fairies till 2014, and also many others… , so if someone can help me in this big task for 2016, please contact me at :

shankar ram
shankar ram
September 16, 2015 21:25

Another cyclic extravaganza by PAP! A stunning and wonderfully unified synthesis of Sentinels, Anti-Andernach and Chinese line piece effects. All the 3 Fairy elements are fully and uniformly utilised in each solution. The use of Sentinels is particularly remarkable:
1. As a direct battery on d6
2. As an indirect battery(via d6) for the Chinese line pieces to guard f6/e4/f5
3. As a WK flight blocker on f6/e4/f5
4. As a hurdle on f6/e4/f5 for the Chinese line pieces to capture the WQ g6/f2/g3 from d6 on the last move
5. As an indirect battery hurdle on h5/h3/h4 for the WPao h6 to guard h1/h2
Anti-Andernach colour changes seen in 4 out of 6 half-moves in each solution.
The W(B!)Q and one of the 3 Chinese line pieces each move 3 times in each solution.
To top it off, model mates and meredith setting.
A sumptuous birthday problem indeed for Julia!


shankar ram
shankar ram
September 16, 2015 21:52
Reply to  shankar ram

More on Sentinels utilisation…!
6. As a hurdle on d6 or f6 for BPao to guard WK flight e6 from a6 or g6
7. As a cook stopper in a) (1.Qf7? doesn’t work!)

shankar ram
shankar ram
September 17, 2015 03:51
Reply to  shankar ram

Oops! In a) W _has_ to generate a BP on g6. So, 1.Qf7? wouldn’t work… even if no BP was generated on f7!

September 17, 2015 06:54
Reply to  shankar ram

Great visual analysys Shankar!

petko petkov
petko petkov
September 16, 2015 23:21

About my No.895

This problem is C+ also according to WinChloe 3,32 – therefore – the Luce`s information is wrong!
About the purity of checlmate – thank You very much, Dear Juraj for your interesting comment! But my opinion is different from your concept – If only one piece guards one unblocked specific square using two lines, this is a weakness – though not quite big. I do not think that the practice of some great masters – as Mandler and Mach (or the practice of some TT) can be an aesthetically law valid for everyone.
This question is really for discussion but I am convinced that such a fact as a minimum is inconvenient from an aesthetic point of view. Therefore, in my opinion, such “duality” must always be avoided, if that is possible!

Luce Sebastien
Luce Sebastien
September 17, 2015 01:11

Sorry about the n°895, it is C+ Winchloe !
(I tested a wrong position)
By the way, as I register alone all the problems of Julia’s Fairies for Winchloe database (the reference base) , I invite all the composers to test their problems with Winchloe, if they to be in the database with the mention C+
Best to all

Kenneth Solja
Kenneth Solja
September 17, 2015 18:24

Dear Petko,
as a composer I feel that I have to doubt every position even if the master has done it.
I’m still unexperienced as a fairy composer and fairy world is not as familiar to me as orthodox chess is.
Nevertheless I did try to economize your problem and in the same time learn something new ..
I agree Petko’s point of view is this case, but I also understand Juraj’s point.

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