Skip to main content
Chess

Return to Answer

indent
Source Link
DTR
DTR
  • 3.1k
  • 1
  • 19
  • 41

If the question is asking why computer engines don't use much narrower opening books that could theoretically be analyzed deeper (and thus be objectively 'better'), the answer is simply that it actually makes the engine weaker because the chance of leaving the book becomes greater with a deep-but-narrow book (as suggested) instead of a shallow-but-broad one.

You could come up with an incredibly detailed book for one specific mainline opening (and some people have tried this, a notable example being for the Halloween Gambit), but there are several problems:

  • If the opening your engine will play is known because there's really only one line used, it's easier to research that and include a refuation in a competing engine's book.
  • If your engine only has a very narrow book, then it's relatively easy to generate an opening book that is broader and using a small amount of randomness in the engine would provide a fair chance of deviating and staying in book long after your engine is thinking for itself (which is generally a bad idea for an engine in the opening).
  • If your engine knows a certain opening up to move 50, then it's not difficult for a competitor to take that book and expand that one opening up to move 55, thereby having a decent advantage. It's a real problem when your book contains thousands of different lines, though.

As a result of these, having a broader book is a benefit both offensively (you might be in book longer) and defensively (less likely to be brought out of book quickly), and requires only a small sacrifice in depth.

If the question is asking why computer engines don't use much narrower opening books that could theoretically be analyzed deeper (and thus be objectively 'better'), the answer is simply that it actually makes the engine weaker because the chance of leaving the book becomes greater with a deep-but-narrow book (as suggested) instead of a shallow-but-broad one.

You could come up with an incredibly detailed book for one specific mainline opening (and some people have tried this, a notable example being for the Halloween Gambit), but there are several problems:

  • If the opening your engine will play is known because there's really only one line used, it's easier to research that and include a refuation in a competing engine's book.
  • If your engine only has a very narrow book, then it's relatively easy to generate an opening book that is broader and using a small amount of randomness in the engine would provide a fair chance of deviating and staying in book long after your engine is thinking for itself (which is generally a bad idea for an engine in the opening).
  • If your engine knows a certain opening up to move 50, then it's not difficult for a competitor to take that book and expand that one opening up to move 55, thereby having a decent advantage. It's a real problem when your book contains thousands of different lines, though.

As a result of these, having a broader book is a benefit both offensively (you might be in book longer) and defensively (less likely to be brought out of book quickly), and requires only a small sacrifice in depth.

If the question is asking why computer engines don't use much narrower opening books that could theoretically be analyzed deeper (and thus be objectively 'better'), the answer is simply that it actually makes the engine weaker because the chance of leaving the book becomes greater with a deep-but-narrow book (as suggested) instead of a shallow-but-broad one.

You could come up with an incredibly detailed book for one specific mainline opening (and some people have tried this, a notable example being for the Halloween Gambit), but there are several problems:

  • If the opening your engine will play is known because there's really only one line used, it's easier to research that and include a refuation in a competing engine's book.
  • If your engine only has a very narrow book, then it's relatively easy to generate an opening book that is broader and using a small amount of randomness in the engine would provide a fair chance of deviating and staying in book long after your engine is thinking for itself (which is generally a bad idea for an engine in the opening).
  • If your engine knows a certain opening up to move 50, then it's not difficult for a competitor to take that book and expand that one opening up to move 55, thereby having a decent advantage. It's a real problem when your book contains thousands of different lines, though.

As a result of these, having a broader book is a benefit both offensively (you might be in book longer) and defensively (less likely to be brought out of book quickly), and requires only a small sacrifice in depth.

Source Link
DTR
DTR
  • 3.1k
  • 1
  • 19
  • 41

If the question is asking why computer engines don't use much narrower opening books that could theoretically be analyzed deeper (and thus be objectively 'better'), the answer is simply that it actually makes the engine weaker because the chance of leaving the book becomes greater with a deep-but-narrow book (as suggested) instead of a shallow-but-broad one.

You could come up with an incredibly detailed book for one specific mainline opening (and some people have tried this, a notable example being for the Halloween Gambit), but there are several problems:

  • If the opening your engine will play is known because there's really only one line used, it's easier to research that and include a refuation in a competing engine's book.
  • If your engine only has a very narrow book, then it's relatively easy to generate an opening book that is broader and using a small amount of randomness in the engine would provide a fair chance of deviating and staying in book long after your engine is thinking for itself (which is generally a bad idea for an engine in the opening).
  • If your engine knows a certain opening up to move 50, then it's not difficult for a competitor to take that book and expand that one opening up to move 55, thereby having a decent advantage. It's a real problem when your book contains thousands of different lines, though.

As a result of these, having a broader book is a benefit both offensively (you might be in book longer) and defensively (less likely to be brought out of book quickly), and requires only a small sacrifice in depth.