Search found 16823 matches

by bob
Wed Nov 06, 2019 7:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: oldie but goody
Replies: 11
Views: 1383

Re: oldie but goody

I think that number is wrong. Sounds more like a sigma 6/7. IIRC, the sigma 9 had a .73 microsecond clock, which would translate to about 1.3MIPS. If every instruction referenced memory it could not run that fast, but it was pretty fast for the day. Today my Apple watch has more computing power. :)
by bob
Wed Nov 06, 2019 5:42 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: oldie but goody
Replies: 11
Views: 1383

Re: oldie but goody

I would be interested, too, Dr. Hyatt. I have one of Jim Ablett's Cray Blitz Windows compiles (running from the command prompt) from 2008. The included source was also written in Fortran. I assume this is your code as well. Yes it was. But for the CB source it was NOT scanned in via OCR. I actually...
by bob
Tue Nov 05, 2019 3:59 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: oldie but goody
Replies: 11
Views: 1383

oldie but goody

I don't know if I have ever released this, but I was looking through old files and ran across a REALLY old version of my chess program. WAY before it had the "Cray" in its name. This is version 6.9, dated 1977, which sounds right. Right after the WCCC that year, I decided to get rid of the highly se...
by bob
Mon Nov 04, 2019 2:45 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Limiting nodes to reduce engine strength
Replies: 20
Views: 2323

Re: Limiting nodes to reduce engine strength

Been playing with this for a couple of days. Using the OPs idea of dynamically adjusting the NPS, plus my original approach of randomizing the evaluation, I have gotten something that works. Nowhere near perfect yet, and calibrating it is a bit difficult. But I took a couple of open-source programs,...
by bob
Fri Nov 01, 2019 6:45 pm
Forum: Computer Chess Club: General Topics
Topic: Tactics cannot be very important for chess
Replies: 90
Views: 5498

Re: Tactics cannot be very important for chess

But what is the "plan"? Has to be to checkmate the opponent's king. If you can't see a way to force that, then you seek a way to reach a position where that goal is more reachable, even if you can't see it. But think about it, the game of chess is not infinite. So it is theoretically possible to sea...
by bob
Fri Nov 01, 2019 5:56 pm
Forum: Computer Chess Club: General Topics
Topic: Tactics cannot be very important for chess
Replies: 90
Views: 5498

Re: Tactics cannot be very important for chess

A strong GM, many years ago, wrote something to the effect "Chess is purely about tactics..." His thinking was the positional play is nothing more than very deep / very long-range tactics. IE what is bad about a backward pawn? It gives you a weakness and your opponent a target. A target that can't m...
by bob
Thu Oct 31, 2019 8:27 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Ubuntu Shell file
Replies: 8
Views: 1067

Re: Ubuntu Shell file

rather than executing the file that does the CD, simply type "source <filename>" and it will execute the cd command and whatever in the SAME (current) process, so that once you source the command and do a "pwd" you will find you are in the new directory. This works for the c-shell as I use it all th...
by bob
Wed Oct 30, 2019 6:13 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Decreasing Depth in MultiPV?
Replies: 14
Views: 1677

Re: Decreasing Depth in MultiPV?

I typically implement multi-PV by adding a few statements in the code that prints a newly found PV (and is thus only executed in the root). Normally alpha-beta would set alpha = bestScore just before this (after a score > alpha was found). The extra statements just lower alpha. As I control multi-P...
by bob
Tue Oct 29, 2019 9:59 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Limiting nodes to reduce engine strength
Replies: 20
Views: 2323

Re: Limiting nodes to reduce engine strength

OK, this topic tweaked my interest, so I am re-visiting this a bit. I eventually will get rid of the skill command and replace it with an "elo xxxx" command. I am currently working to establish the rating at 6M nodes per second, which is what Crafty runs on my MacBook using just one thread. I am goi...
by bob
Tue Oct 29, 2019 7:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Decreasing Depth in MultiPV?
Replies: 14
Views: 1677

Re: Decreasing Depth in MultiPV?

How will that work? After completing the first move (NOT necessarily the best move) if you start on the second best move with a +/- infinity alpha/beta bound, how can the search be efficient? You did lots of pruning on this move on previous iterations, but now, suddenly, you can't due to the a/b win...