Problem 6631 / 41129: old wine in new bottles

[revenant]

Hello, I see that Problem 6631 has been disabled and replaced by Problem 41129.  Since the initial position is the same, would it be possible to carry the existing comments over so users can benefit from the (sometimes considerable) investment of CPU time and organization of the variations that went into the analysis?  You could display a tag on each re-adopted comment to explain that portions of it may no longer apply to the current move order.  It might forestall a fair number of repetitive questions & gripes.

If that's not feasible, a good halfway measure would be to at least put a pointer to the old problem ID on the new ID's page, just as the old ID's page already says where the new one is.

I'm also curious as to what is the nature of the change.  Is it a different alternative being accepted somewhere?  Is it a result of the most recent generator run?  These are useful bits of information you might want to summarize somehow on the old ID's page ("Disabled *because*..." ambiguity, threshold, alternative, etc.).

CT keeps making great progress!

[richard]

There are a few reasons why one problem replaces another, sometimes the pruning algorithm changes and the new problem has a different number of moves than the original. More recently , alternatives have been the source of most replacements.  Sometimes if the problem has been given a different amount of CPU time in one run over another the actual main line move choices can change.  At the moment I don't keep this information in a conveniently accessible form so I can't present the details to the user.

The two main reasons I don't bring comments over from the old problems to the new ones is that 1) they are often no longer irrelevant as they may relate to elements of the old problem that no longer exist and 2) PR reasons. This is related to the first reason , but often the reason a problem was replaced is because it sucked in some way that the new generator has fixed.  Some users are quite blunt when a problem sucks and even if they are clearly marked as "old comments" I think it can give new users the wrong impression of the overall problem set quality in the improved sets if the old problem comments are able to live on after the generator problems are fixed.  I can see how this may look a bit like censorship and in a way it is but the comments on a replaced problem really don't belong on the new one, it is a different problem after all. 

I could have my arm twisted into making the "replaced by" link bi-directional , in that way the archeologists amoungst us who like digging into the ancient ruins of the problem set can still get their fix :-)  It might be interesting to allow a "disabled" problems option on the problems list and even the problem search and custom problem set creation.  Not all of the disabled problems are terrible, many of them are simply collateral damage in the war against poor quality problems.

Regards,
Richard.