Here I have a game where I experimented with sanrensei as Black. Unfortunately my opponent left, but I'm interested to who was leading when he left and if Black made some bigger mistakes before, so feel free to give me your opinion.

As far as my japanese tells me, your opponent told you that he has to leave because he has no more time.

I think the current fight is very important for the outcome of the game. If you win, you win by a lot. Otherwise white wins.

Your biggest mistake in my opionion was B81. Would have played this at N7/O7 to support the right group. If this group is strong, his Q10/Q13 is very,very weak.

A 7 kyu would have played N8 aiming at L11 or K7. He expects to get the center, the bottom or the right side.

Throughout the game, B played fast and loose, attacking often but rarely taking time out to defend cutting points or make a base for a weak group. Take a look at the position after move 48. The lower left group at G4 has not made a base, the lower right connection between O5-Q6 can be cut, and the upper right string of stones is too thin to be called a wall. At this point, I think the best plan for B is to defend some of these weaknesses, build up strength before launching another attack. Connecting solidly around O7 would be good. Or consider K3, making a base for the lower left, attacking the W lower side, and indirectly defending the lower right.

The attack at move 49 seems dangerous, at least before some of the preparations suggested above. The continuation up to move 58 gives B a huge moyo, but the stones below become very weak. Playing like this is possible -- B gets enough territory above to win, provided he does not get killed below. But to be consistent, B *must* extend at G10, and if W continues to push for another move or two, B must continue to extend. When B takes time out to defend at G6, letting W crush the moyo with G10, the B strategy has failed. Once you have started a sequence like this, play it out consistently! If you find a way to make sabaki below, it will be a satisfying win If those stones all die, you will hopefully learn to be more cautious in your attacks in the future