This generalizing definition can be applied to all pieces and types of chess games in which a hurdle-piee is used and it makes an additional movement (second step) after the move of the piece that jumps through it. On this reason the Bul principle works very good on “Hoppers arena” but also on the Chinese chess. The second step here completely copy the moves of the playing figure. But note that this principle can be used also in an other way: second step but with other rules, but it will be theme of an other article.
1. Any piece X that has the ability to play (with the capture or without capture) jumping over another piece (in the role of hurdle) Y (own, enemy, king, pawn, etc).
2. After such a jump, as a second, compulsory part of the move, Y must make only one non – capturing movement (second step), imitating a move of X. If such imitation is impossible, the move of X over Y is illegal. The second movement of Y must be chosen by the side which plays with X.
3. If the hurdle Y is also a Bul piece, it performs, as a second step of the move, only one movement imitating the piece X in its standard form.
4. In the role of Y a Pawn can move or capture one step forward everywhere on the board, except on its 2nd rank, where it can move two steps forward.
Follow the definitions from the WinChloe program that I use in the originals I offer today.
BUL GRASSHOPPER (code BG) – Definition (according to WinChloe where the French name is Sauterelle Bul, code PAB):Moves like a Grasshopper ((0,1)+(1,1) Hopper), but the hurdle must also make a Grasshopper move (the move is impossible if it cannot). BUL LION (code BLI): Definition (according to WinChloe where the French name is Lion Bul, code LIB):Moves like a Lion ((0,1)+(1,1)Prolonged Hopper), but the hurdle must also make a Lion move (the move is impossible if it cannot). BUL PAO (code BPA): Definition (according to WinChloe where the French name is Pao Bul, code PAB):Moves like a Pao ((0,1)Chinese), but the hurdle must also make a Pao move (the move is impossible if it cannot). BUL VAO (code BVA): Definition (according to WinChloe where the French name is Vao Bul, code VAB):Moves like a Vao ((1,1)Chinese), but the hurdle must also make a Vao move (the move is impossible if it cannot).
No.1518Petko A. Petkov Bulgaria original – 29.06.2020 Dedicated to Christian Poisson!
First of all, let's pay attention to the construction wBGh3, w.Ph2, b.Kh1. Here the black king is not under check from BGh3, because the hurdle (wPh2) has no second step! Therefore, we could call this construction as a Potential Bul Battery or as a Deactivated Bul Battery, because at the beginning it did not work yet.
The deactivated Bul battery, however, has huge potential power, as show the solutions of this original. In the beginning, for example, the move 1 ... Bc7?? is an illegal self - check, because after it the battery is activated and the second step Ph2->b8 (Q,R...) is already possible. For the same reason, illegal are the moves 1... Rff4?? of 1...Rbf4?? (in both cases the second step Ph2->e5 is possible) or the moves 1 ... e2 ?? (wPh2->d2), 1... Rb2 ??(wPh2->a2).
But the big paradox in this problem is an other effect: if, for example, on the diagonal h2-b8 we put two pieces : Bc7 and Rd6, it turns out that these figures are pinned by the battery: each move of Bc7 is illegal due to the second step Ph2->c7, and any move of Rd6 is also illegal due to Ph2->b8.
Now we can say that the main theme here is the creation of two systems of such double pins on two thematic lines - the diagonal h2-b8 and the 2nd horizontal! Stepping on the second horizontal, the neutral Rook also becomes motionless, for the reasons mentioned in point 3, but the nR guards the fields around the black king.
Summarizing: here we have model pin-mats with 4 pinned pieces (2+2) in each solution, and in total in both solutions the thematic figures occupy 8 different squares! An additional motive is the double Annihilation of the black pawns c5 and е3 with goal to open the line for the w.B.
Some important technical remarks. It is necessary on the Bul diagram the figures of different types (Bul G, Bul Lion, etc.) to be placed with the usual symbols, but in squares, in order to differ from their standard analogues or from other fairy pieces that participate in the play.
My recommendation is to use the powerful Bul Lion only when is needed to show the typical Lyon effects. It would not be good if in a problem the composer could express his theme with Bul Grasshopper, but instead he use Bul Lion. Here is an easy problem that shows the use of Bul Lion with some its typical effects: Petko Petkov (Education example): White: Ke1, BLIg2(2); Black: Kf7,Bh2, Pa2, Pb4, Pe3, Pg7(6) - H#2, 2 solutions: I.1…BLIg8(Pe7) 2.a1=BLI BLId5(Rb7) 3.BLIg1(Ke4) BLIa8(Kh1)#.II.1…Ke2 2.Kg8 BLIc2(Ke8) 3.Bc7 BLIc8(Bh7)#.
(Author)
No.1519Petko A. Petkov Bulgaria original – 29.06.2020 In Memoriam to my mother
Danka Petkova
White Kf7
White Royal BVa4 BPd5
Black Ka8 Ba7 Sb8 Pb7
h#2 (3+4)
b) bSb7, c) +bSb6, d) +bSc8
Bul VAO a4 ; Bul PAO d5
{JV: Temporary no animation as the author prefers
to have frames around the BUL pieces, what in Popeye/Py2Web
works for defined behavior attributes only. }
a) 1.Ba7-d4 BPAd5-a5 2.Bd4-a1 BPAa5*a1
[wBVAa4->a6]#
b) bSb7
1.Sb7-c5 BVAa4-c6 2.Sc5-e4 BVAc6*e4
[wBPAd5->c6]#
c) +bSb6
1.Sb6-c4 BVAa4-b5 2.Sc4-a5 BPAd5*a5
[wBVAb5->d5]#
d) +bSc8
1.Sc8-e7 BPAd5-b5 2.Se7-c6 BVAa4*c6
[wBPAb5->a4]# (C+ by WinChloe 3.50)
The problem is dedicated to the memory of my late mother Danka Petkova (1920-1993) on the occasion of the 100th anniversary of her birth.
The problem is of the so-called HOTF type in H# gemre (I named this type ANI (2+2).
In the FIRST DUET: positions a) and b) , the thematic elements are: opening of the anti - battery line and sacrifice of the black piece. On the matting moves, of the fields a6(a twin) and c6 (b twin) after a Bul effects, the Bul PAO/Bul VAO block the black Sb8.
In the SECOND DUET: twins c) and d) , after reciprocal moves of the white pieces on b5 square, follow captures with Bul effect, which lead to mates by double checks and exchange of the starting places of the white pieces.
Unusual but correct formation of twins - here in each twin there is no more than one change in position.
Model mates.
Chinese pieces with a Bul modification were invented by Petko Petkov and after his final analysis on this figures in March -Aprсl,2020, at the suggestion of Petkov to Christian Poisson in WinChloe 3.50 were programmed some kinds of this units (Bul PAO, Bul VAO). In all possible Chinese pieces with a such Bul modification (aslo Bul LEO, Bul PAO,Bul VAO, Bul NAO, Bul RAO, etc) the piece (hurdle) makes an additional movement (second non capturing step) which copies the movement of the capturing figure. In fact, in LЕO, PAO, VAO, etc., for example, the second step exactly copies the route of a Queen, Rook, Bishop respectively but the hurdle retains its kind.
The exact names of these pieces in English are Bul Pao (code BPA) and Bul VAO (code BVA). In French the names are PAO Bul (code PAB) and VAO Bul (code VAB) Technically, on diagrams these pieces should be marked with theirs usual symbols , but enclosed in a square to distinguish them from the standard Chinese pieces.
No.1518,1519
As written under the diagram, c) and d) don’t have a solution because of 3.Sb7-a5.
I think that the 2 ‘+’ signs should be removed from the twinnings.
c) +bSb6, d) +bSc8 indicates the changes related to the diagram. It’s not c)=b)+bSb6, so there’s no bS on b7 but bP.
Don’t write rubbish, Thomas!
The ‘+’ signs mean “add piece” of course, not continued twinning.
Sorry for my confusion.