Most of the time what happened with is i am in good position ,sometimes clearly winning.but suddenly in some move i blunder...what is the reason?is this due to over playing chess?

There could be many reasons: fatigue, unfamiliarity with the position, not checking for threats first, time pressure, etc. Here are a couple videos by GM Smirnov I saw about preventing blunders that are decent, though I didn't think they were particularly outstanding...

How to Eliminate Blunders?

https://www.youtube.com/watch?v=_N0E0eahWnQ

How to Eliminate Blunders? (PART-2)

https://www.youtube.com/watch?v=xASlcNhMXwg

Smirnov's suggestions:

1. Warm up before the game.

2. Focus on chess.

3. Avoid tactical openings when your opponent is better prepared.

4. Keep track of your opponent's plans.

5. Anti-blunder check.

6. Grasp the initiative.

7. When you are short of time, SIMPLIFY the position.

8. Solve tactical puzzles from THE OTHER side.

He said that #4 and #5 alone will help you to eliminate 80% of your blunders.

thank you sqod!

recently i lose a game by blunder.....lazy to play both piece ur oppenent piece and blindfold field......just share....yeah anti blunder youtube video is really great video

Because we are human...

why we blunder?

Because we are patzers, which means "blunder", "error", or something like that in German.

https://en.wiktionary.org/wiki/patzer

 English[edit]

Etymology[edit]

Origin uncertain; perhaps from German Patzer.

Pronunciation[edit]

• (UK) IPA^(key): /ˈpatsə/

Noun[edit]

patzer ‎(plural patzers)

1. (chess, slang) A poor player; an amateur.  [quotations ▼]

External links[edit]

• Wikipedia article on chess.

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See a lot of analysed games with blunders in:

http://www.chess.com/forum/view/game-analysis/the-most-interesting-game-of-chess-was-played-here-in-chesscom

@ MarcoBR444

we are poor player thats why we blunder this is not the solution .but if we know the reason ,then we can work on it and become a good player.that is why I asked so many good players can help us...