Pins?!

[jesper_nielsen]

I don't know if it is good idea for a strategic test suite, but perhaps pins could be considered?

When to prevent them and when to make them.

Some engines include pins in their evaluation function, but others don't.

Kind regards,
Jesper

[jesper_nielsen]

I don't know if it is good idea for a strategic test suite, but perhaps pins could be considered?

When to prevent them and when to make them.

Some engines include pins in their evaluation function, but others don't.

Kind regards,
Jesper

Oops!

Sorry!

I thought I replied to the STS ideas thread.

[swami]

Hi Jesper, It's a really good idea. But most of the pins occur in tactical type positions. Our goal is to collect positions that are strategical/positional in nature, as best as we can.

I'd add Pins - that don't involve material gain so the idea remains strategical as opposed to tactical.

Strategical version of "pin" - forces opponent to take the passive role and lose the mobility of his pieces by defending the pinned piece. Doesn't gain material but limits the activity of opponents piece.

Tactical Version of "Pin" - threatens to gain material via absolute or relative pin.

Thanks for the idea. I've updated the ideas page with the added "strategical" pin here

[michiguel]

Hi Jesper, It's a really good idea. But most of the pins occur in tactical type positions. Our goal is to collect positions that are strategical/positional in nature, as best as we can.

I'd add Pins - that don't involve material gain so the idea remains strategical as opposed to tactical.

Strategical version of "pin" - forces opponent to take the passive role and lose the mobility of his pieces by defending the pinned piece. Doesn't gain material but limits the activity of opponents piece.

Tactical Version of "Pin" - threatens to gain material via absolute or relative pin.

Thanks for the idea. I've updated the ideas page with the added "strategical" pin here

It will be a great idea for a test suite, but it is rarely strategic. Anyway, I am interested in those type of positions in which you are pinned, you do not lose anything, but that pin creates tremendous problems. You have to pay too much energy to defend that particular piece for so many moves...
Generally it is combined with horizon effects.

Gaviota suffers from this and it is in my to-do list to address it. It lost one game the other day on ICC for this very reason against a WIM.

Miguel

[Dann Corbit]

Hi Jesper, It's a really good idea. But most of the pins occur in tactical type positions. Our goal is to collect positions that are strategical/positional in nature, as best as we can.

I'd add Pins - that don't involve material gain so the idea remains strategical as opposed to tactical.

Strategical version of "pin" - forces opponent to take the passive role and lose the mobility of his pieces by defending the pinned piece. Doesn't gain material but limits the activity of opponents piece.

Tactical Version of "Pin" - threatens to gain material via absolute or relative pin.

Thanks for the idea. I've updated the ideas page with the added "strategical" pin here

It will be a great idea for a test suite, but it is rarely strategic. Anyway, I am interested in those type of positions in which you are pinned, you do not lose anything, but that pin creates tremendous problems. You have to pay too much energy to defend that particular piece for so many moves...
Generally it is combined with horizon effects.

Gaviota suffers from this and it is in my to-do list to address it. It lost one game the other day on ICC for this very reason against a WIM.

Miguel

The related idea of overworked pieces is scheduled for the Swami treatment.

For the most part, pins, skewers and x-ray attacks are pretty well revealed by SEE, are they not?

The exception (of course) is overworked pieces which will gradually succumb to pins added one at a time.

[Kirk]

I don't know if it is good idea for a strategic test suite, but perhaps pins could be considered?

When to prevent them and when to make them.

Some engines include pins in their evaluation function, but others don't.

Kind regards,
Jesper

If you want to specifically target pins, it is one of the variables one can modify in Prodeo. It works well!

http://www.top-5000.nl/prodeo.htm

[bob]

Hi Jesper, It's a really good idea. But most of the pins occur in tactical type positions. Our goal is to collect positions that are strategical/positional in nature, as best as we can.

I'd add Pins - that don't involve material gain so the idea remains strategical as opposed to tactical.

Strategical version of "pin" - forces opponent to take the passive role and lose the mobility of his pieces by defending the pinned piece. Doesn't gain material but limits the activity of opponents piece.

Tactical Version of "Pin" - threatens to gain material via absolute or relative pin.

Thanks for the idea. I've updated the ideas page with the added "strategical" pin here

Most books use pins as part of a tactical motif, but I have seen quite a few positions over the years where a pin is critical. In one case, a black king on g7, black pawns on f7,g6,h7, black knight on f6. White pinned the knight with a bishop, and now the game is won for white. The black king could not escape the pin, could not break the pin (due to other pieces/pawns on the board) and the final result was that it locked the black king on g7 for many moves as black had to waste time to set up things to break the pin, while white did what it wanted elsewhere.

Those kinds of positions would be useful. The result of the pin was a loss, but it was _way_ beyond any possible search horizon. What one needed was to realize that the pin effectively locked the black king on g7, while the black king really needed to centralize to prevent white's king from penetrating and winning pawns on the queen-side.

It was deep enough that the search would not show the win, so the eval had to realize that if the king was stuck around g7 it was in serious trouble. Some of those kinds of positions would be pretty useful, although one does not need to actually evaluate the pin to solve them, but you do need to know that for some unknown reason, the king can't reach a good square, until by luck you expose the plan to break/avoid the pin and move on...

[bob]

Hi Jesper, It's a really good idea. But most of the pins occur in tactical type positions. Our goal is to collect positions that are strategical/positional in nature, as best as we can.

I'd add Pins - that don't involve material gain so the idea remains strategical as opposed to tactical.

Strategical version of "pin" - forces opponent to take the passive role and lose the mobility of his pieces by defending the pinned piece. Doesn't gain material but limits the activity of opponents piece.

Tactical Version of "Pin" - threatens to gain material via absolute or relative pin.

Thanks for the idea. I've updated the ideas page with the added "strategical" pin here

It will be a great idea for a test suite, but it is rarely strategic. Anyway, I am interested in those type of positions in which you are pinned, you do not lose anything, but that pin creates tremendous problems. You have to pay too much energy to defend that particular piece for so many moves...
Generally it is combined with horizon effects.

Gaviota suffers from this and it is in my to-do list to address it. It lost one game the other day on ICC for this very reason against a WIM.

Miguel

The related idea of overworked pieces is scheduled for the Swami treatment.

For the most part, pins, skewers and x-ray attacks are pretty well revealed by SEE, are they not?

The exception (of course) is overworked pieces which will gradually succumb to pins added one at a time.

If you pin a queen on a king with a rook or bishop, it is obvious and is of no real use in a test position. But some pins simply restrict the opponent's mobility, and they need to be avoided or broken as soon as possible. Those are interesting since they don't win material outright, but may well lead to a long-term winning position because of the lack of mobility for the pinned piece, or any defending pieces.

[michiguel]

Hi Jesper, It's a really good idea. But most of the pins occur in tactical type positions. Our goal is to collect positions that are strategical/positional in nature, as best as we can.

I'd add Pins - that don't involve material gain so the idea remains strategical as opposed to tactical.

Strategical version of "pin" - forces opponent to take the passive role and lose the mobility of his pieces by defending the pinned piece. Doesn't gain material but limits the activity of opponents piece.

Tactical Version of "Pin" - threatens to gain material via absolute or relative pin.

Thanks for the idea. I've updated the ideas page with the added "strategical" pin here

It will be a great idea for a test suite, but it is rarely strategic. Anyway, I am interested in those type of positions in which you are pinned, you do not lose anything, but that pin creates tremendous problems. You have to pay too much energy to defend that particular piece for so many moves...
Generally it is combined with horizon effects.

Gaviota suffers from this and it is in my to-do list to address it. It lost one game the other day on ICC for this very reason against a WIM.

Miguel

This may not be the best test position, but it illustrates the idea. Neja (WIM) vs Gaviota on ICC.

It takes 33 seconds for Gaviota to avoid Bxa2 Ra1 Bxc3 bxc3 and the Ba2 is pinned forcing the Q and B to be out of play for ever. No material is lost; however, the white attack on the K side is unstoppable after that.

[D]r4rk1/pp1nppb1/2p1b1pp/q1p5/4PP2/2NPBNQP/PPP3P1/1R3RK1 b - - 1 13 am Bxa2

[swami]

Hi Jesper, It's a really good idea. But most of the pins occur in tactical type positions. Our goal is to collect positions that are strategical/positional in nature, as best as we can.

I'd add Pins - that don't involve material gain so the idea remains strategical as opposed to tactical.

Strategical version of "pin" - forces opponent to take the passive role and lose the mobility of his pieces by defending the pinned piece. Doesn't gain material but limits the activity of opponents piece.

Tactical Version of "Pin" - threatens to gain material via absolute or relative pin.

Thanks for the idea. I've updated the ideas page with the added "strategical" pin here

It will be a great idea for a test suite, but it is rarely strategic. Anyway, I am interested in those type of positions in which you are pinned, you do not lose anything, but that pin creates tremendous problems. You have to pay too much energy to defend that particular piece for so many moves...
Generally it is combined with horizon effects.

Gaviota suffers from this and it is in my to-do list to address it. It lost one game the other day on ICC for this very reason against a WIM.

Miguel

This may not be the best test position, but it illustrates the idea. Neja (WIM) vs Gaviota on ICC.

It takes 33 seconds for Gaviota to avoid Bxa2 Ra1 Bxc3 bxc3 and the Ba2 is pinned forcing the Q and B to be out of play for ever. No material is lost; however, the white attack on the K side is unstoppable after that.

[D]r4rk1/pp1nppb1/2p1b1pp/q1p5/4PP2/2NPBNQP/PPP3P1/1R3RK1 b - - 1 13 am Bxa2

Splendid example, Miguel.

I was looking for positions where Strategical variant of Pin occur and I found this:

q3r1k1/3p1pb1/pp6/2p1n1p1/PP1p4/5PP1/2PPQ1KP/1R4NR b - - bm g4; id "STS(v7.0) Strategic Pin.001";

[d] q3r1k1/3p1pb1/pp6/2p1n1p1/PP1p4/5PP1/2PPQ1KP/1R4NR b

g4!

A lot of pieces are cramped, defending the f3 pawn. Some engines may choose cxb4 or Nc6 but with more time they would change the plan to g4.