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MatPlus.Net Forum General Cyclic Babson Selfmates-How many cycles have been correctly shown?
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(1) Posted by Rewan Demontay (Real Name: James Malcom) [Monday, Sep 7, 2020 22:44]

Cyclic Babson Selfmates-How many cycles have been correctly shown?

Henry Bettmann’s famous s#3 shows the classical QQ-RR-BB-NN combination. But it also known, as Peter Hoffmann has demonstrated, that 23 other promotion patterns are present as well. Naturally, selfmates achieved them long before direcmates. How many cycles have been correctly shown to date? Preference is given to s#3s over s#4s if possible, and a promotion key, per tradition, is also favored more.

I only of the three, so that’s 4/24 in total. Who know of more?

Horst Deichelbohrer, Schach-Echo 6/1976, s#3
(= 14+8 )

Daniel Itzhaki. Die Schwalbe 2/1976, s#3
(= 15+8 )

Walther Jørgensen, Die Schwalbe 03/1952, 1. Preis Inf.T., Richter: D. Nixon, s#3
(= 14+11 )

Additionally, here is a cooked QB-RN-BR-NR to further get the idea across. The cook is that 1.... b1=N is met by 2. Q,R,B,S.

Jan Knöppel, Udvalgte Skakproblemer 1955 s#3
(= 15+6 )

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(2) Posted by Andrew Buchanan [Tuesday, Sep 8, 2020 14:29]

Joke fix for poor old Knöppel: shift wLc1 to h6, wDd7 to g8, remove wBg7h7, add Black dummy pawn on c1/d1. If the Album judges in 1964 didn't spot the cook, maybe they wouldn't spot the dummy pawn today :-)

(= 13+7 )
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(3) Posted by Rosie Fay [Wednesday, Sep 9, 2020 10:28]

Just to correct your info about the Jørgensen: the pattern of promotions is QN/RB/BR/NQ i.e. the lower the Black piece, the higher the White piece (if we take Q>R>B>N). Source: PDB P1019454.
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(4) Posted by Rewan Demontay (Real Name: James Malcom) [Wednesday, Sep 9, 2020 13:08]

That was my source as well, Rosie-error corrected and thanks.
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(5) Posted by seetharaman kalyan [Monday, Sep 14, 2020 11:50]

Babson is for matched promotion. Better not call other patterns by that name
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(6) Posted by Rewan Demontay (Real Name: James Malcom) [Monday, Sep 14, 2020 13:12]

Well then, what do you propose we call them, seethmaran? The fact that they have been called "Cyclic" ensures that, IMO< they are not known as the classical Babson Cycle. The task of matched promotions in a direcmates took such a long time to do that the name was embedded into everyone's heads/. It'd be really hard to knock it back out.
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(7) Posted by Viktoras Paliulionis [Monday, Sep 14, 2020 22:16]

The Encyclopedia of Chess Problems by Milan Velimirovic and Kari Valtonen uses the term "Babson task" for classical Babson and "Shifted Babson task" for cyclically shifted Babson.
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(8) Posted by Andrew Buchanan [Tuesday, Sep 15, 2020 04:16]

I think “cyclic” is too limiting, as it only covers 6 of the 24 possible permutations. In computer science, “shift” does mean a cyclic permutation. It has a more general sense but I think the CS sense is dominant for our geeky community. There’s also the question of whether (AC)(BD) is cyclic - it’s certainly a shift in CS terms! Any Babson is hard work - it doesn’t dilute the value of the term to allow all 24 permutations. So for clarity and to avoid changing the encyclopaedia definition, we could talk about “permuted Babsons”.
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(9) Posted by Viktoras Paliulionis [Tuesday, Sep 15, 2020 10:23]

I agree that it is difficult to create a problem with two AUWs (black and white), but I'm not sure if each AUW pair should be called Babson.
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(10) Posted by Andrew Buchanan [Tuesday, Sep 15, 2020 10:53]

Well “Nabobs” is an anagram of Babson :-)

Seriously, the door is already opened in the Encyclopedia to the term (cyclic) “shifted Babson”, and I see no reason to stop with only 7/24 Patterns recognised. “Permuted Babson” is a natural generalization and will confuse no-one

A definite lower rung in PDB today is occupied by the keyword “3/4 Babson”. Does that “cheapen the brand”? I don’t know: I think it’s ok and it’s very descriptive. “Close but no cigar” as they used to say
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(11) Posted by Jan Hein Verduin [Tuesday, Sep 15, 2020 11:55]

I think I already said this somewhere else, but Meindert Niemeijer used to call a Babson where the promotions don't match inadequate. Not as condescending as it sounds; adequate can mean 'matching'.
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(12) Posted by Andrew Buchanan [Tuesday, Sep 15, 2020 12:06]

The basic Babson idea is so cool that’s it’s natural to want to extend the idea, and this involves zero artistic compromise: indeed a cyclic version of an s#3 may be harder to set up than one whose order as a permutation is 1 or 2, because in the latter case, the symmetry simplifies the geometry. E.g. if there is a key square where R grabs N, then it will be easier to find a corresponding square where N grabs R. There’s thus greater thematic variety and unity in a cyclic Babson
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(13) Posted by Hauke Reddmann [Tuesday, Sep 15, 2020 20:06]

@Jan Hein: <innerstjoke>As a chemist, I have no qualms with INADEQUATE :-)</innerstjoke>

* Incredible natural-abundance double-promotion transfer experiment :-))
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MatPlus.Net Forum General Cyclic Babson Selfmates-How many cycles have been correctly shown?