Test position

[peter]

Also, it is far from clear to me that the Salai win study (Sachova Skladba/4 EG#16028, 2011, 1p. Heijden database #3465)

[d]4K1k1/8/1p5p/1Pp3b1/8/1P3P2/P1B2P2/8 w - - 0 1

has a major dual at move 1, as was claimed on some other threads. After the proposed dual 1. Bd1!? (1. f4!), black has 1...Bd2 2. f4 B:f4 3. Kd7 Bd2 4. Kc6 Ba5 5. b4 c:b4 6. Bb3+ the position repeats the main line one move delayed.

To me as for my personal pov, it's not major dual in sense of a big deal neither.

But after 1.Bd1(!?) Black hast not only ...Bd2 leading to transpostion after 2.f4, but with 1...Kg7 White yet has to have another way "of it's own" to win, as I showed in some other postings to that great study, with 2.Kd7, because then 2.f4 wouldn't work.
Of course after 2...Bd2 then, there's again transposition with 3.f4, again one could say, so what?

That's exactly, what I meant, 1.move f4 not the only winning move, ok with transpos. to 2.f4, 3.f4 still ok, 5th or 6th f4, with ways of their own to that, still ok?

Yes to me and to you, but we both didn't have to judge the first price of the study in Sachova Skladba 2011, and I really don't know, if the dual was known then already.

Let's be not too sophisticated, if we agree at this one example anyhow, that it's one of the most beautiful pieces, let's leave it for good.

[MOBMAT]

I think the use of "dual" in most cases comes from using the Chest mating engine. Anytime it finds more than one mate WITH the same depth, it outputs "Duals(x)" where 'x' is the number of mates.

Not to be confused with the more academic definition that was mentioned earlier in this thread.

What is the best way to convey "multiple mate in x's" ?

[peter]

I think the use of "dual" in most cases comes from using the Chest mating engine. Anytime it finds more than one mate WITH the same depth, it outputs "Duals(x)" where 'x' is the number of mates.

Not to be confused with the more academic definition that was mentioned earlier in this thread.

What is the best way to convey "multiple mate in x's" ?

With Chest "All solutions" and CompleteDuals", with Gustav "Alle Lösungen suchen", with game playing engines MultiPV- mode.

[MikeB]

I think the use of "dual" in most cases comes from using the Chest mating engine. Anytime it finds more than one mate WITH the same depth, it outputs "Duals(x)" where 'x' is the number of mates.

Not to be confused with the more academic definition that was mentioned earlier in this thread.

What is the best way to convey "multiple mate in x's" ?

If WTM, "white wins easily" , if BTM , "black wins easily" ;>0

[MOBMAT]

I think the use of "dual" in most cases comes from using the Chest mating engine. Anytime it finds more than one mate WITH the same depth, it outputs "Duals(x)" where 'x' is the number of mates.

Not to be confused with the more academic definition that was mentioned earlier in this thread.

What is the best way to convey "multiple mate in x's" ?

If WTM, "white wins easily" , if BTM , "black wins easily" ;>0

If the "bm" tag is used in a FEN along with the "dm", and there are multiple moves with the "bm" tag, then I would interpret that to mean that there are multiple moves that have the same "mate in X" value. This is needed when using automated processes to determine if an engine actually finds the mating move. Not just one that also mates but takes longer.

It is just as bad when a FEN has only one move that is a mate in x, but there is in fact another move that is also a mate in x (same x). if the engine chooses the missing move, it will not get credited for finding the mate.

so, perhaps the best way to convey the moves is to say, "there are multiple "bm"'s. LOL