Why am I so bad at chess?

I feel like I throw away every game with a stupid blunder that could easily be avoided. 

I looked at your last two 15/10 games. You spent no time thinking. Part of the thinking process is a blunder check before you move. You shouldn't be losing with more time on your clock than you started. At 15/10 you have 30 seconds to think for 40 moves, no including your opponent's time. Use the time.

Take time before moving, as others have indicated; watch out for checks, captures and threats. Perhaps play Rapid on 30 minutes - this is my own favourite set-up. Especially recently I have been trying to make each individual move I make the best possible move. Especially at relatively lower levels of play this may be the best way forward - cut down on the blunders and perhaps your opponent will make more serious errors. Not exactly scaling the heights of chess, but committing fewer errors is the first step.

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