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KoBul Kings - Part 1

dkvideo(22.02.2014) Here you can see my article about KoBul Kings which was published in The Problemist, January 2014. Hope you like it!

The Problemist, January 2014

KoBul Kings - Part 1

by FM Diyan Kostadinov



            The idea of creating this new fairy condition come to me at the beginning of 2010 as a result of my research and interest in the possibilities of the different fairy King types and Royal pieces. The creation of the final version of KoBul Kings was a process with some changes and decisions about the basic idea until the beginning of the WCCC Crete 2010, which was a good opportunity to present it. The new fairy condition (during that time presented as a new type fairy piece – KoBul King) was a theme for the first „Bulgarian Wine Tourney” in WCCC 2010 where I also presented a lecture about it.

            Nowadays the KoBul Kings are becoming more and more popular, with about 150 published problems in many chess composing magazines, websites and formal tourneys. The problems of this kind can be tested with Popeye and WinChloe. The name KoBul (King) is combination of „Ko” from Kostadinov and „Bul” from Bulgaria.



            KoBul Kings - When a piece (not a pawn) of his own side is captured, a King transforms into a Royal piece of the same type as the captured one. When the King is in the form of any Royal piece and there is a capture of one of the pawns of his own side, he becomes a normal King again. 

Captures are illegal if they result in self-check by the transformed King. 

Castling is allowed only if the KoBul King is on his initial square in the form of a normal King and if he has not already moved; however he may already have been transformed. 

In the case of capture by a King in AntiCirce he is reborn on his initial square and may castle. If the capture is by a King which is in the form of some Royal piece, he is reborn on the initial square of that piece.

A Royal piece is one which is not allowed to be captured. If a Royal piece is threatened with capture and cannot avoid capture next move, then the game is lost by checkmate. (Readers unfamiliar with some fairy forms in this article could look them up on the website KoBulChess.com on the following direct link: http://kobulchess.com/en/definitions/fairy-pieces-and-conditions.html )



The easiest and clearest notation is as follows: “K” – King, “rB” – Royal Bishop, “rR” – Royal Rook etc. So in the case of capture resulting in transformation of the King the notation is as in the following example: the black King is in its King phase and White captures a black Bishop on c2 with a Rook on move 1, so the move is: 1.Rxc2(bK=rB) 

      1) Scheme

            - In 1 Black cannot castle because this is allowed only if the King is in his „King” phase. But castling is possible after 1…c4 2.Rxc4(brB=K) 0-0+

            - The white Rook cannot capture the black Knight on g6 because this will be self-check by transforming the black Royal Bishop into a Royal Knight: 1.Rxg6(brB=rS)?? self-check (illegal move)

            -The white King can capture the black Knight on g6, because after the transformation  of the black Royal Bishop into a Royal Knight the square g6 will not be guarded as in the initial position: 1.Kxg6(brB=rS)

            -Possible helpmate: 1…Se7 2.Kxe7(brB=rS)#

            -Another possible helpmate variation is: 1…Se5 2.Rg6 Sf7 3.Kxf7(brB=rS)#, but if the white Rook tries to protect square d6 from d4 this will not be mate, because after 1…Se5 2.Rd4? Sf7 3.Kxf7(brB=rS)+ black has the defence 3…cxd4(wK=rR)!! which transforms the white King into a Royal Rook and this negates the check from f7.



This article will be separated into two parts with 4 chapters in total:

- chapter 1: Problems without other fairy pieces or conditions;

- chapter 2: Problems with other fairy conditions;

- chapter 3: Problems with other fairy pieces;

- chapter 4: Problems with other fairy pieces and conditions.


Chapter 1: Problems without other fairy pieces or conditions


            There are still not so many KoBul Kings directmate twomovers, but I believe that many interesting and paradoxical ideas and mechanisms can be found in this area. Here I will present only one such example.

2) 1.Rf3? (zz), 1…Sxf3(wK=rR)!? a 2.Qc1# A, 1…Sxe2(wK=rB)!? b 2.rBe7# B,

1…Sh3 c 2.Bxb4(bK=rR)# C, 1…Sf~ 2.Rc6#, 1…Kd6 2.Rxf6(bK=rS)#, but 1…h3!

   1.Bf3! (zz) 1…Sxf3(wK=rB)!? a 2.rBe7# B, 1…Se2 b 2.Bxb4(bK=rR)# C,

1…Sxh3(wK=rR)!? c 2.Qc1# A, 1…Sf~ 2.Rc6#, 1…Kd6 2.Rxf6(bK=rS)

   Very interesting use of KoBul Kings to create a Lacny theme. There are also effects of black correction in the thematic moves by the black Knight.


            In the helpmate genre there are very good possibilities for creation of original problems with interesting thematic complexes. The most natural are presentations of different types of Royal batteries, promotions, sacrifices etc.

3) a) 1.Be4 Ra5+ 2.Kf4 Rf5# [3.Kxf5(wK=rR)?? self-check]

    b) 1.rQd5 Ra3 2.rQh1 Rxh3(brQ=K)#

    c) 1.rRe8 Rf4 2.rRg8 Rf8# [3.rRxf8(wK=rR)?? self-check]

    d) 1.rBh2 Ra1 2.Rg3 Rh1# [3.Bxh1(wK=rR)?? self-check]

    e) 1.rSd3+ Ke2+ 2.rSb2 Rb4# [3.Rxb4(wK=rR)?? self-check]

   An unbelievable task showing a full set of five Forsberg twins in miniature form!

4) 1.Qf6+ Sxf6(bK=rQ) 2.rQxe7(wK=rB) Sxh7(brQ=K)# (2…Sd7??)

    1.Qe5+ Sxe5(bK=rQ) 2.rQxd5(wK=rR) Sxf3(brQ=K)# (2…Sc6??)

The initially pinned Knight becomes the front piece of a fairy battery, ODT.



            In selfmates with KoBul Kings the transformations of the Kings may lead to some interesting mechanisms with defensive and offensive fairy effects.

5) a) 1.h6! Kf7 2.Re8 Kxe8(wK=rR) 3.Rd7 Kf8 4.Re7 Kg8#

    b) 1.Kh6! Ke7 2.Rg8 Kf7 3.Re6 Kxg8(wK=rR) 4.Rf6 Kg7#

Chameleon echo mates in Rex Solus and only 5 pieces on the board!


            This problem type has become very popular in the last few years and the connection with KoBul Kings is very interesting and promising.

6) a)  1…Sd6! 2.Qa4+ Sxa4(wK=rQ) 3.rQxa4(bK=rS)+ Qxa5(wrQ=K)#

[3…Qxd4(wrQ=K)?? Impossible] [4.Kxa5(brS=rQ)?? illegal move - selfcheck]

    b)  1…Sb6! 2.Qc3+ Sxc3(wK=rQ) 3.rQxc3(bK=rS)+ Qxd4(wrQ=K)#

[3…Qxa5(wrQ=K)?? Impossible] [4.Kxd4(brS=rQ)?? illegal move - selfcheck]

A fairy version of the Zajic theme in mating position, white/black BiValve on B1, change of functions between the black Knights, ODT, Meredith and nice fairy play.

7) a) 1.Sb3! Rd5!! 2.Bxd5(bK=rR) rRd1 3.Bxe4(brR=rB)+ rBxb3(wK=rS)# [4.rSxc3(brB=bK)?? self-check]

    b) 1.Sc4! Bd5!! 2.Rxd5[bK=rB] rBe4 3.Rxd1(brB=rR)+ rRxc4(wK=rS)# [4.rSxc3(brR=bK)?? self-check]

White Nowotny on d5 combined with double capture of black thematic pieces and battery-creation. Reciprocal effects in play of 4 pieces (Rd8, Ba8, Rd1, Be4). Preliminary white line-closing by the Sa5 – with additional goal – sacrifice of this piece, model-mates with thematic effects on the mating-move.


8) a) 1…d3 2.Qf1 gxf1S(wK=rQ) 3.exd3 Se3 4.rQxe3(bK=rS)+ Qxd3(wrQ=K)#  

[5.Kxd3(brS=rQ)?? selfcheck]

    b) 1…Qe6 2.Qh1+ gxh1B(wK=rQ) 3.e3 Bf3 4.rQxf3(bK=rB)+ Qxe3(wrQ=K)#   

[5.Kxe3(brB=rQ)?? selfcheck]

Sacrifices, minor promotions, fairy Zajic theme, Ideal mates, Miniature.


                The presented problem shows that the condition can be used in seriesmovers, but the full potential of the piece is slightly limited and can be seen fully only on the last move.

9) a) 1.d1S! 2.Sxb2(wrB=K)! [2.Sc3? 3.Sa4 4.Sb6 5.Sc8+ dxc8S(bK=rS)+ 6.rSc6!] 3.Sa4 4.Sb6 5.Sc8+ dxc8S(bK=rS)#! [6.rSxc8(wK=rS)?? selfcheck]

   b) 1.d1Q! 2.Qxe2(wrB=K)! [2.Qg1? 3.Qg4 4.Qc8 5.Qb8 cxb8Q(bK=rQ)+ 6.rQd7+!] 3.Qg4 4.Qc8 5.Qb8 cxb8Q(bK=rQ)#! [6.rQxb8(wK=rQ)?? selfcheck]

S-S and Q-Q matched promotions, KoBul Kings effects.


            I believe that in Proof Games and Retro problems many complicated and unusual ideas can be realised. I am still waiting to see a Retro problem which involves a dual avoidance play or thematic tries with KoBul Kings effects.

10) 1.h4 d5 2.h5 d4 3.h6 d3 4.hxg7 dxc2 5.d4 a5 6.Be3 c1Q 7.Qxc1(bK=rQ) rQa4 8.Rh6 b5 9.Rb6 Sh6 10.g8Q Bg7 11.b4 Qxg8(wK=rQ) 12.rQc3 Sd7 13.rQc6 Sf8 14.rQe8 axb4(rQ=K)15.Qc6 rQd1 16.a4 rQe1 17.axb5(rQ=K)

This PG shows 2 promoted Queens (one for each side) captured without having moved. This trick is impossible in an orthodox PG! Both Kings exchange their initial squares.


Chapter 2: Problems with other fairy conditions 

The combination of KoBul Kings with other fairy conditions provides many interesting effects and possibilities.


11) a) 1...a1Q! 2.a8B!! Qxa8(wK=rB) 3.rBf4 c1B! 4.bxa8R(bK=rQ)+! rQxa8(wrB=rR)#

      b) 1…a1R! 2.a8S!! Rxa8(wK=rS) 3.rSb3 c1S! 4.bxa8Q(bK=rR)+! rRxa8(wrS=rQ)#

White and black AUW, 6 captures and 8 different pieces playing to a8 in total, corner to corner play, pawns only position.

12) a) 1.f1R [f1B/S?] Ka7 [Kb7/Kc7?] 2.Rf3 exf3(bK=rR)#

      b) 1.f1B [f1S/R?] Kb7 [Kc7/Ka7?] 2.Bd3 cxd3(bK=rB)#

      c) 1.f1S [f1R/B?] Kc7 [Ka7/Kb7?] 2.Se3 dxe3(bK=rS)#

Very nice problem with wK mates after transformations and KoBul Kings/ Madrasi effects, three promotions and cyclic dual avoidance.

13) 1.Rd8 Rxc4(bK=rB) 2.Rxc8(wK=rB)+ rBe4==

      1.Bb3 Bxd7(bK=rR) 2.Bxa4(wK=rR)+ rRh6==

Reciprocal pins and captures, diagonal/orthogonal echo



14) 1.Se5 Kxc2-e4(bK=rB) 2.rBxc8-h8(wK=rR) rRxe5-d7(brB=rS)#

      1.Sd8 rKxa3-a5(bK=rR) 2.rRxc3-h8(wK=rB) rBxd8-e6(brR=rS)#

Creation of white Royal batteries, change of functions and dynamic play typical of T&M.

15) a) 1…Kb4 2.b1S Kxc4-a2(bK=rB) 3.rBe1 Kxb1-d2(brB=rS)#

      b) 1…Kb5 2.b1B Kxc4-c1(bK=rR) 3.rRh8 Kxb1-h7(brR=rB)#

Durbar, under-promotions, good twinning, model mates, miniature.



16) a) 1.Ba8! Rxc4(bK=rR) 2.rRa1 Rc1#  [rRxc1(wK=rR, wRa1)??]

      b) 1.Rc8! Bxe4(brK=rB) 2.rBh3 Bg2#  [rBxg2(wK=rB, wBf1)??]

Check avoidance first moves and fairy mates, change of functions.


17) a) 1.c1S! Kxc1(bK=rS, wKe1) 2.rSxb7(wK=rR, brSg8) rRe8#

        b) 1.c1R! Kxc1(bK=rR, wKe1) 2.rRxd4(wK=rB, brRh8) rBc3#

Change of functions of the white pieces, miniature.


Chapter 3 and 4 will be included in Part 2 of the article.

For any questions or comments please use the comments form under the article or email me: This e-mail address is being protected from spambots. You need JavaScript enabled to view it  



+1 #1 Diyan Kostadinov 2014-02-24 21:18
The five problems noted as "The Problemist 2014" were originals for the article. Many thanks to their authors!
+1 #2 seetharaman 2014-02-25 04:19
Bala's No.12 is a beauty where he shows the unusual Kobulchess effect of releasing the Madras Rex paralysis! I like the dual avoidance effects.
+2 #3 Nikola Predrag 2014-02-25 23:28
A nice idea where the promotions determine the square for wK with sacrifices which unparalyze wK in the end. I'm sorry but I can't easily detect the links which would close the cycle.
Writing solutions as a)1.f1R(f1B/S?) is completely absurd, a form of 3 solutions begins with all 3 possible keys. Any twin-problem contains such "key-tries".
Economy seems good, but wSd6 is too "expensive" and hardly acceptable in a helpmate. This should be avoided, the following rough example is rather non-economical but at least "acceptable". It probably could be improved.
W:Pa6,Pd6,Kc5,Pd5,Pe4,Pd3,Pg2,Ph2; B:Pb7,Pc7,Ka5,Pa4,Pc3,Pe2
Another possibility for improving would be white piece(s) with real functions in all phases.

(I wonder how it became a regular custom to use "Dual avoidance" in cases where nothing is avoided. Avoiding means that some possibility is DISabled. Here, the promotions and sacrifices ENable the mates. I would call it perhaps "Unique allowance".)
+2 #4 Geoff Foster 2014-02-28 21:21
No.2 and No.12 are analysed in the March issue of The Problemist Supplement, which will appear in a few weeks.
+1 #5 Diyan Kostadinov 2014-02-28 21:42
Thanks for information Geoff! In the March issue of The Problemist the readers will find also the Second Part of the article KoBul Kings (with fairy pieces).

Also - thank you Nikola for your educative comment. Actually your proposed "rough example" (as you call it) can be easy improved - for example wPe4 is not needed and personally I prefere the twin form but with 2 wPs less. For examlpe:
Of course probably even better version is possible, but I have not enough time to search for it...

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