One of the most common questions I'm asked by my students is: How can I blunder less frequently? 

Naturally there are many different types of blunders and causes for those blunders. However, let's define a blunder first, so there can be no confusion between silly mistakes and decisive ones:

Blunder: A very bad move which makes our position considerably worse than it was before, such as from winning to equal, or equal to losing. 

Back in the old days (pre-2005), you were able to write your move down on your scoresheet before making it, and this served as an excellent way to 'blunder-check', but this is no longer allowed in the FIDE Laws of Chess as it is considered a form of note-taking. One thing we should accept is that the only way we can avoid ever blundering again is to stop playing chess, but that wouldn't be very fun...in any case, mistakes are part of the game and the struggle between two players. 

Let's start with the game in the photo above:

It would be easy to attribute the loss to a slip in concentration, but I think the reason Black lost concentration in this example is because he knew the endgame is, with best play, a draw and therefore let his guard down. You have to concentrate on every single move of a chess game - if you lose focus for one move, you can very easily undo all the work you put in beforehand. This applies regardless of the position in front of you. 

When you find yourself thinking that you have a winning position or a drawn position, don't let yourself relax - continue trying to find the best move on each move, whether it's the surest way to win or the clearest way to draw. 

While blunders are usually of a tactical nature, they can also be strategic/positional blunders, as the following game shows:
Admittedly White's blunder could be attributed to overlooking 36...Ne4, but I've labelled this as a strategic blunder because Black would still be much better even without this move. The way to minimise such oversights is to look for aggressive moves by the opponent on your half of the board, which threaten something. In this case, 34...Re3! and 36...Ne4! was the way to exploit the weakening of White's king safety. It should be added that White was under some pressure earlier in the game, which provoked the blunder that a player of Korchnoi's class would normally not make. 

Another good way to reduce our blunders is to have a good sense of danger. For instance, if your king is under attack, you should make doubly sure that the opponent has no forced checkmate before you go grabbing material on the other side of the board. However, opening the position when we are well behind in development can be just as deadly, as the following example illustrates:
The move 8...Nxe4 isn't one that can be proven to be losing by force in a game, but it should be rejected on the basis that it loses too much time in what is quite a sharp position. As for 11...Nh5, this oversight could have been avoided by considering all of White's forcing continuations and continuing to do so down each move of Black's calculations (though in his defence, Black's position was already quite bad). The way to reduce such mistakes is to appreciate the importance of rapid development when the position is open or about to be opened, and of course be well prepared to avoid similar traps in the future.

When club players ask about avoiding blunders, they usually mean moves that hang material or unnecessarily allow checkmate. So in the next fragment we will see a case where the White player simply had a blind spot.
Another major type of blunder is that of assumption, where you assume that the opponent has to make some response to your move, when in fact they have something much better, but that's such a broad topic (with many types of possible assumptions) that I'll save it for another blog post. Instead, I want to finish up with an example illustrating how blunders often arise when we lose our objectivity and try to garner more from a position than what we deserve. 
This was a long post so let's sum up the blunder-reducing techniques we have learned:

  1. Concentrate on finding the best move in a reasonable amount of time in every position. It doesn't matter how well you played earlier if you make a blunder at the end, so when you are clearly winning or in a dead drawn position, try and find the surest way to win or hold your draw. 
  2. Blunders can be strategic as well as tactical. Many strategic blunders involve weakening key squares with some pawn move or making a bad 'equal' exchange of pieces, so take the time to judge who benefits more from the change in the position. 
  3. Keep a healthy sense of danger. If you lose a lot of time grabbing a pawn and open lines in front of your king while your pieces are undeveloped, the chances are the pawn grab is unsafe, and you'd be better off continuing development and castling your king. 
  4. To avoid really silly blunders, use 'Blumenfeld's Rule' and double-check the really basic stuff like whether you are getting mated or if one of your pieces is unsafe. 
  5. Another good technique is to check for forcing moves (moves which threaten to win material or checkmate) in your half of the board.
  6. When you reach the end of a line in your calculations from a fairly critical or sharp position, check one move further to make sure you haven't missed anything important. 
  7. We can improve our concentration by not thinking about the opponent's rating, the result of the game and other extraneous data not related to finding the best move on the board.
What you learn from one opening can often be used in other openings!

Chess players often think about they can improve their understanding of the openings, and this only becomes more frequent as you rise through the ranks. What a lot of players overlook is that you can learn a lot about the middlegames arising from your opening by taking the most common pawn structures from that opening, and seeing examples from other openings where one of those structures also arises.

For instance, I recently wrote a post about the Meran Semi-Slav on my other blog (for SAC) where I talked about how the following structure is in White's favour:

The same pawn structure can arise in the Catalan, only where White has played g2-g3 (and sometimes b2-b3) and Black has often played ...b6 at some point to get his light-squared bishop out! However, the ideas are often the same. 
With this knowledge, we now know how to play these positions as White when Black plays ...c5, and also when he doesn't break with ...c5. I've seen a lot of club players walk into these positions as Black against the Catalan due to a lack of theoretical knowledge, and you can score a lot of points by being aware of the standard methods to obtain and convert your advantage. 

Of course, strong players will see what's coming and have something prepared for when you break with e4, such as the ...c6-c5 counterthrust! Let's check it out in our next game. 
Obviously the Catalan is way too complex to master from studying just two games, but you should have a much better idea of how to handle the typical pawn structure - and you can carry this knowledge with you to several openings, not just the Catalan! The next time you want to improve your openings, broaden your horizons and use good ideas from other openings to strengthen your understanding of the middlegames that crop up from your repertoire!

If you enjoyed and learned from my article, please share it and consider having some chess coaching to receive my insights into every phase of the game - and most importantly, how to become a stronger player as rapidly as possible!