Why did the engine play so poorly?

I just finished a game with the Chessmaster 9000 personality "Josh - Age 12 (2100)", with 10/10 Fischer time controls:

In move 3 it offers a bizarre bishop-for-bishop trade which results in it doubling a pair of its pawns and opening up a file and diagonal that most players wouldn't want opened up this early in the game, and for no good reason that I can see.

Then in move 9, it offers a knight-for-knight trade which doubles another pair of its pawns, again, for no good reason that I can see.

In move 17 it offers a pawn-for-pawn trade which results in it giving away a pawn for free, isolating its doubled pair of pawns in the process, and again, I can't see why it did it.

So even though it has voluntarily screwed up its pawn structure, and given away a pawn, it practically insists on trading down to a king & pawns endgame, making matters worse for itself.

Does anyone have any idea what it was "thinking"? This is the sort of gameplay I'd expect from a personality with a supposed 1200 rating, not from one with a supposed 2100 rating.

It's an old program. I think it was brought out in 2002.

The ratings were based on slow chess, like 40 moves in 80 minutes.

In a 10 minute game with a 10 second delay per move, the computer will be much weaker. 

I am also wondering if you have the opening book installed. I agree it seems unlikely that Josh would have played 3.. Be6,

It is old, but the default "Chessmaster" personality is quite strong, even in fast games. I played it against Rybka a couple years ago with 3/1 Fischer time controls, both programs running on this same PC, and it was a draw:

I've also played other personalities; one of my favorites is:

"Vlad

Rating: 1846

Unorthodox openings, Very Fast"

He moves instantly every time (which is the main reason I like playing him, i.e., no waiting), regardless of how much time you give him (with 10/10 his clock doesn't even go down; he'll have 5 or 6 more minutes than he started with by the end of an average game). Despite his lightning fast moves and significantly-lower-than-2100 "rating", he doesn't make ridiculous moves. I find him to be a difficult opponent.

As far as I know, there is no way to turn the opening book off in CM9000. Back in the early '90s I had the Super Nintendo version of Chessmaster, and it had an option to turn the opening book off, but if CM9000 has that option, I haven't found it. It does have an "Opening Books" folder in its installation folder, with 76 files:

The 3...Be6 move in the first game is strange. Josh Age 12 should be using the WaitzkinJ.obk opening book. I looked at the book via the opening book editor, and that move isn't in the book. Josh should have played either 3...Nc6 or 3...Nf6.

You can change settings in a personality that comes with Chessmaster 9000, but it will give the modified personality a new name, such as Josh Age 12 #2. (The original Josh Age 12 personality will still exist, with no changes.)

If you create a new custom personality, I think you can specify any opening book, even NoBook.obk. (I haven't tried not specifying any opening book, but I suspect you could do that.)

I made a mistake regarding Josh's 3rd move in the first game. I didn't notice that the move weightings for 3...Nc6 and 3...Nf6 were set to zero. (They can be set to 0%, 25%, 50%, 75%, or 100%.) I'm not sure exactly how the weightings work, but I guess that with the only two book moves set to a zero weighting, Josh was effectively out of book at that point. So, while 3...Be6 might not be a good move, at least it doesn't mean that the opening book wasn't being used properly.

That's interesting. I wonder how these personalities work. With a supposed 2100 rating, it shouldn't be making moves like that, regardless of being out of book. "Vlad" never makes moves like that, and it's rated much lower, and doesn't even use its available time (moves instantly no matter what).

You can look at the personality settings for each personality, and maybe get some clues. For example, Vlad has a strength of play of 100 versus about 50+ for Josh Age 12, but Vlad only looks 3 plies deep, while Josh looks much deeper.

I don't know what either you or it were thinking. Why Nh4? Ng5 and Qg4 is good for white!

I asked myself the same question afterwards.

Chess engines are baned by Chess.com =a form of cheating=leave them alone=they can be monitored= YOU will be baned

The site offers a chess engine for members to play against. I guess Chess.com will have to ban itself.

This is a bizarre, out-of-left-field post if I ever saw one. I'm not sure where your point of confusion lies exactly. Are you under the impression that I was playing a 12-year-old kid named "Josh" here on Chess.com and consulted an engine for help during the game? This thread is about a game between a chess engine and me, and no one else.

I've never even played a game against anyone on Chess.com; I haven't played online chess in ages. Back in the early '00s I played chess for a few months on Yahoo Games, and that kind of soured me to the whole online chess thing. I had some fun games, but the negatives outweighed the positives. For example, most of the time, instead of playing chess, I'd be waiting around to find someone who wanted to play a relatively slow game (at least 10/10). Most of them wanted to play 1/0. On top of that, people with a significantly higher rating rarely wanted to play, because it was of little benefit to them if they won, and a big hit to their rating if they lost. Then there were all of the abandoned games, which often happened after someone made a blunder or otherwise found themself in a losing position, and instead of resigning, they would just let the clock run down.

I thought Plavin's post was a hoot. He obviously didn't understand the thread.