Fridges +The Marshall

Isn't it so that computers go entirely nuts when they are sure the position is completely lost?

Originally posted by tvochess
Isn't it so that computers go entirely nuts when they are sure the position is completely lost?

I'm not sure about that.

Think about this though. You are in a lost position.

There are three moves to choose from.

Move 1: You simplify to an ending a bishop down that should lose by force. The computer has you at -2.79 or something (not looking all the way to the end).

Move 2: You withdraw from the attack and lose a pawn or two more. The computer only has you at -2.5 , but you no longer have any counterplay whatsoever.

Move 3: You make a dodgy rook sacrifice. The computer has you at -4.80. Two moves into the sacrifice, your opponent has 3 choices - one clearly loses, one leaves material even but your opponent on the defensive, and the third has a deadly trap in it but does win if he finds 3 more correct moves.

The computer will almost always choose line 1 or 2 even though they really give the losing side no chance. It has calculated out choice 3 and sees that it loses. Unfortunately, humans sometimes don't have the mental accuracy (especially in the heat of battle) or the nerves to find all the correct moves to survive the rook sacrifice line. Even though, it's not the computers best choice, it is still a human's best chance (provided he is playing against another human).

Computers are able to walk on razors with variations 5 moves deep or more with only a single line that survives and come out on top. I guess that's a real advantage of being able to calculate thousands of positions a minute!

I guess this is just a more general repeat of what I already posted, but I thought another example may be helpful to some.

Hi Paul,

I've have a sleep, now back onboard.

tvochess is right as well.
God only knows how many trillions of lines the thing looked at.
Some of these odd moves will be to stave off some distant mate that it is impossible to see OTB.
Also if it thinks it is lost it will grab at the best evealuation it can see.
Hence the nonsense is splurted out.

Lundin all those years ago comes up with that Rf5 idea.
It is a human idea backed up with human experience.
It does appear it is unsound but OTB it presents problems for the defender
to solve and that is all we can do.
(I'm not even sure if he saw the Rb5 line v Qb6. All Lundin gives is Rf5!!)

It's not the first unsound idea to appear in analysis. Unsound ideas pop up in
games all the time and often win. Without them brilliancy game books will be
half empty and I would have lost 75% of my games. 😉

Once again it's not Proper Knob's fault, he is just the messenger.

(The Duck just told me he was out for a swim this afternoon and some nutter
nearly hit hik with a CD tied to a brick. Sounds like PK has done the Proper Thing.) 🙂

Seems a bit disjointed but following from comments on the blog, here is the game O'Donnell - Grant from round 3 of the Scottishl



according to the Championship website the winner was born in 1999.

oh and this also happened in round 3;



Black had been holding his own against top opposition when madness struck; Knights can move backwards