Fritz 15 is unsuitable for analysis.

[A Distel]

[D]3nbK2/2nqp1PP/4pkP1/5pp1/6r1/b7/1p6/8 w

Fritz 15 is not able to under promote with a bishop so it's unsuitable for analysis.

[hgm]

That is a debatable statement. Bishop promotion virtually never occurs in practice.

Better would be to say it is not suitable for solving some highly contrived problems that one would never encounter in a real game.

[Henk]

Skipper does. So Skipper is better than Fritz 15 !! I remember supporting under promotion costs some ELO.

[Dann Corbit]

That is a debatable statement. Bishop promotion virtually never occurs in practice.

Better would be to say it is not suitable for solving some highly contrived problems that one would never encounter in a real game.

I have 3558 positions in my database that involve Bishop under-promotion.
Most are composed problems but some are from games.

If you consider all the possible moves that should be considered during the search, I guess that it comes up more than you think.

Here is the result of some grepping through the PGN output of TCEC games:
https://www.dropbox.com/s/3udja8gph5m21 ... t.txt?dl=0

You will see that there are around 300 Bishop under-promotions during the course of all of TCEC that show up in the pvs. Of course, a few of the engines may not even be able to consider these moves.

Of course, there will be many other under promotions that were considered but did not become pv nodes.

The point being that sometimes Bishop under-promotion is the right move. When Bishop under-promotion is the right move (perhaps the only way to win or draw) and the engine suggests another move, then the engine is simply wrong. In analysis I can give as much time as I want, so we do not have tournament time pressure.

I agree with the assessment:
Fritz 15 is utterly unsuitable for analysis.

Great for game play, perhaps, but an engine that does not under-promote should not be used for analysis because it is defective.

[hgm]

How many of these Bishop promotions were because the piece would be taken immediately anyway, and the engine just picked a random one?

[Evert]

I never really understood the reason for omitting bishop under promotions. I was under the impression that there was a technical reason, but I can't find it again and I can't think of one either.

I can think of some reasons to reduce (or even prune/omit, if near the leaves) under promotions since they're approximately never useful, but I see no reason to single out bishop under promotions from the other possibilities. Anyone know a reason why?

[A Distel]

That is a debatable statement. Bishop promotion virtually never occurs in practice.

Better would be to say it is not suitable for solving some highly contrived problems that one would never encounter in a real game.

Yeah, but sometimes, less is more! And the engine player in us loves to see the underpromotions bishop feature in real good chess engines.

[Norm Pollock]

deja vu

http://rybkaforum.net/cgi-bin/rybkaforu ... l?tid=1042

[h1a8]

That is a debatable statement. Bishop promotion virtually never occurs in practice.

Better would be to say it is not suitable for solving some highly contrived problems that one would never encounter in a real game.

I have 3558 positions in my database that involve Bishop under-promotion.
Most are composed problems but some are from games.

If you consider all the possible moves that should be considered during the search, I guess that it comes up more than you think.

Here is the result of some grepping through the PGN output of TCEC games:
https://www.dropbox.com/s/3udja8gph5m21 ... t.txt?dl=0

You will see that there are around 300 Bishop under-promotions during the course of all of TCEC that show up in the pvs. Of course, a few of the engines may not even be able to consider these moves.

Of course, there will be many other under promotions that were considered but did not become pv nodes.

The point being that sometimes Bishop under-promotion is the right move. When Bishop under-promotion is the right move (perhaps the only way to win or draw) and the engine suggests another move, then the engine is simply wrong. In analysis I can give as much time as I want, so we do not have tournament time pressure.

I agree with the assessment:
Fritz 15 is utterly unsuitable for analysis.

Great for game play, perhaps, but an engine that does not under-promote should not be used for analysis because it is defective.

tbh I never heard of or saw where a bishop promotion is better than a queen or rook. Can you please post a position or two? From real games of course.

[Norm Pollock]

A bishop promotion comes into play when a Queen or Rook promotion creates a stalemate.