I played 25 games so far with a 1625 rating. I chose to play Kanna (1592). On the 8th move, she is dropping pieces left and right. It wasn't because of my great moves, but her blunders. I dont think this will happen in real life. Is it a bug in the software? Can someone explain, thanks.

Kanna is 1592? I just looked at the personality, and it says 1588...

At any rate, I wouldn't call it a bug. Every personality has some intentional flaws; hence the different ratings and styles of play.

If you look at the information that goes with Kanna, it says that she's blanced, but that she sometimes forgets about king safety...

It's not a bug. It's a way to dumb down a computer so that we patzers can play with them without getting demolished.

You say that this wouldn't happen in real life?
Perhaps not such a "brain-dead" blunder, but ALL games played on (at least) sub 2200 level are decided by blunders.

Don't let those occasional silly moves fool you, the personality is still generally playing at indicated strength.

Read this excellent article on why does computer play such silly moves and why aren't we satisfied with such wins and want them to make "inteligent mistakes".

http://www.chessbase.com/newsdetail.asp?newsid=2579
(it's a long but interesting read)

quote:

Originally posted by KHollister:
Kanna is 1592? I just looked at the personality, and it says 1588...

Be careful there! The ratings for most of the personalities will change depending on CPU speed. Also note that, because the CPU speed calculation is done every time you launch the program, the same personality can have different ratings between sessions.

jm

quote:

for most of the personalities will change depending on CPU speed. Also note that, because the CPU speed calculation is done every time you launch the program, the same personality can have different ratings between sessions.

Ah, that explains it...

Thanks for the information!

And actually, I was a little disappointed that there is no FAQ that is similar to the one that I wrote for CM8000-CM9000 (ok, well, maybe there IS one, but I can't find it anywhere). That one was fairly technical and, in particular, answered this question.

You can find the old CM8000 FAQ here:
http://chessmaster8000.ubi.com/faqs8000.html

Here are the three Q/As from it that are pertinent (but it is, of course, a bit outdated because CM8000 was released, what, eight years ago?):

Q: How are the ratings for the computer personalities calculated?
A: The rating for the Chessmaster personality is based on several factors: the Swedish Rating List (SSDF) for the engine in Chessmaster 6000 on a Pentium 90 processor, an estimation of the strength of the NEW version of The King, based on the SSDF's rating of the OLD version, and several thousand computer vs. computer and human vs. computer games. The SSDF rating was converted from the Swedish scale to the U.S. scale and an adjustment was made for later improvements to the chess engine. Then a series of computer vs. human and computer vs. computer tournaments were played (a total of almost 14,000 games, about 3,000 of which were human vs. computer) at a time control of Fischer 5/10 (five minutes, plus 10 seconds for each move). The results of these games were fed into a ratings calculator. Each of the personalities has a base rating as measured on a Pentium II-233 (the minimum spec processor for Chessmaster 8000). When you run Chessmaster 8000 on your system, the program performs a CPU benchmark measurement and adjusts the ratings accordingly. That formula is [Base Rating] + 50 * ln([Your CPU Speed] / [Base CPU Speed]) / ln(2). A reasonable rule of thumb to use is that each doubling of CPU speed results in a rating increase of 50 points.

Q: How accurate are the ratings for the personalities?
A: The ratings are mathematically precise, but they are mostly based on computer vs. computer games. While the human vs. computer games added much more "real-world" accuracy to the ratings, many of the Chessmaster personalities have quirks in their playing styles that a human will be able to exploit but a computer opponent will not be able to "see". Discovering and then taking advantage of these weaknesses is part of the fun of Chessmaster, but you might find yourself able to defeat certain personalities that you don't think you should be able to based on their ratings.

Q: The Chessmaster personality shows a rating of 2800 (or more). That certainly can't be "accurate", can it?
A: Strictly based on the math described above, it IS accurate. However, there is a problem of "diminishing returns" as computers get faster and faster, especially at shorter time controls. The difference between a Pentium III-1Ghz processor and a Pentium III-1.2Ghz processor is not going to be as significant. As the Chessmaster personality reports higher and higher ratings, this value should be considered as more of a "benchmark" of your computer's speed, rather than a "real-world" chess rating.

jm

I'll include this in the current FAQ right away...

quote:

Originally posted by KHollister:
I'll include this in the current FAQ right away...

Be careful. I certainly wouldn't copy it verbatim, as some of the details (such as CPU min spec) do not apply to CM GM. I don't know what sort of contacts you have with the development team (if any), but I would recommend that they take the entire CM8000 FAQ and update it however they see fit before it gets put onto this forum.

jm

Hi, John.

Official site from Chessmaster 9000 was even better and had two FAQ's - gameplay and general. Any idea why it was taken down? It's not logical that CM8000 site is still working but CM9000's was taken down.

I believe it just has to do with the URLs involved with the CM8 and CM9 websites. When the CM9 site was created, the web guys migrated all of the CM8 content to chessmaster8000.ubi.com. But when CM10 came around, it appears that they just wrote over all of the CM9 stuff.

But that's just my guess....

jm

I don't think this was the case, because it was still working for a year or two after 10th edition was released. Now I see that the 10th edition site has vanished too. It redirects you to the Grandmaster edition page.

I guess the CM8000 page is still working only because they simply forgot about it

I'm hovering around 1000, and I would say almost all the games I lose are because of a blunder. It is releaving to me that the computer sometimes makes similar blunders, but I haven't noticed it making too many of them, even at my level. Of course at my level maybe I wouldn't notice?

I think I'm going to play Kanna soon!

Kanna didn't make too many stupid move with me. In fact, she won.

I need to study the end game. I seem to be really good at snatching defeat from the jaws of victory.

I don't feel too badly, though. I'm picking up the game again after not playing it for almost 25 years.