Bring on the next opponent! Fisher clock, up to five minutes. 15 kyu, just like me. Although I'm more 14 kyu and even leaning towards 13 kyu at the moment on OGS. Ranks don't say that much at this point I guess.
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Not giving up after a loss. Trying to make that comeback, come up with a new plan to take the advantage!
Pressuring my opponent to get what I want.
Studied invasions yesterday and successfully made one (although it ended badly later, but that was not the invasion's fault!)
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Missing an obvious atari and losing a bunch of stones. Keep sight of the entire board.
Maybe wanting to play too safe near the end. Some of those moves are okay for now, but at a higher level they can ruin your endgame. Safe is okay, but too safe instead of gaining more points is not okay.
I don't tenuki enough. There are often hotter areas on the board.