Originally posted by robbie carrobie
[fen]rn3rk1/pp3ppp/2pqpn2/8/1P2P1b1/P1NP1NP1/5PBP/R2Q1RK1 w - - 1 15[/fen]
in the above position i played the move e5 forking the queen and the knight which was
apparently a mistake, it seemed to me to be such a natural choice, it forced ...Bxf3 exd6
...Bxd1 and Rfxd1, after which i perceived that my newly formed passed d pawn would
need blo ...[text shortened]... hat can i do to avoid making mistakes like this in the future
many thanks i advance - Robbie.
I think it is about how you assess positions. After the preliminary forced sequence we arrive at this position with Black to play his 17th move:-
So do you see this as
A: a passed d pawn that can cause trouble and may need blockading OR
B: a doubled isolated pawn on an open file?
If you see it as A you might play e5; if B you might reject the move.
So why do you think 15. e5 is apparently a mistake?
My engine records a drop from +0.20 to -0.30 either side of 15. e5 which isn't really enough to help
me understand what is going on. To me it means the algorithms evaluate the pawns more of a liability than an asset. In compensation you could argue that you are ahead in development, have more space under control and more options for your pieces so I am not sure. What shall we do - sandpaper some wood off a black pawn and see if that makes things clearer?
In the game I'm not sure that we saw Black make a determined effort to exploit the supposed weakness but we did see you harass him quite hard and he may not have had as many options as one might think at first glance. A deeper analysis is required to see whether his position holds the chances that "a doubled isolated pawn on an open file" would suggest, or if he was simply too cramped to get going.
I think making an accurate evaluation of both sides chances from the position when you decide to play 15. e5 is quite difficult and requires greater skill in "positional judgement" than I possess.
In that sense it can feel like luck as to whether you can win because at the time you make a critical decision you can't be sure your advantages outweigh your weaknesses but you have to play as if they do.
So, when you played the fork if you didn't see doubled isolated pawns that is one thing. If you did and assessed or analyzed your compensating chances as outweighing the weakness that is another. If you have subsequently found a winning line for black that he missed which overturns your assessment then that is a third. In any case you should have a clearer sense as to when doubled isolated passed pawns on an open file can be exploited and whether you would allow them to occur in your position given the choice in future. Maybe only if you can see a forced mate!
All in all an interesting thread.