In the penultimate round in Paris, I played a sandbagger 6d and this position occured.
Tsumego 1: White to do something in Black’s territory.
I was not aware of his strength until after this guy defeated the past champion in the next and last round, even though I played him personally. That is because I (Black) got far behind by playing a nonsensical sequence in the very beginning of the game, after which he didn’t take me seriously anymore:p
The game eventually became close after my opponent gave in to my moves everywhere, but I never got the lead. And at this point White found some magic in my territory, and the game became hopeless after that T__T
(Game) White exchanges 1, 3 and 5 and revives one dead stone by escaping at 7, while threating the three adjacent black stones.
It’s a trap!
If Black rescues the three stones, White can descend twice at 4 and 6 to extend his liberties, and cut at 8.
Black is going to lose one of the groups cut by 8.
Tsumego 2: White to do some more things to Black’s territory
(Game) Of course, I was very smart and saw through White’s plan. And I even found a way to defend my stones on the right side that threatens the capturing of four stones at A, in order to compensate for White capturing at B.
Well, turns out something else still worked X_x
(Game) Unfortunately, White could cut at 11 and atari at 13.
If Black takes at 4, the kosumi at 5 becomes sente, and again White can cut at 7. So in this case my defense was useless.
(Game) But Black can descend at 14.
Now White can neither extend the liberties of his two stones inside, nor threaten to cut.
Or so I thought:p
(Game) I forgot that White could cut from the other side…
After the extension 17, a ko is inevitable. Black cannot avoid it, whatever Black plays.
(Game) In the game I chose to take the liberties of White’s two stones on this side. It became a ko that was direct for Black and one-stage for White. That way I could play some semi-threats that do not threaten anything immediately, but create several more threats.
However, White played this ko perfectly and I resigned shortly after.
Had I defended inside my territory instead of the sequence in tsumego 2, I would have been behind anyway, so I guess this didn’t change the outcome of the game.