guile: The seq is already in the review (i m sorry i missed it) with an appropriate comment (i think) : Its possible but very dangerous for the marked stones.
guile: I will explicit the choices and add seq (correct the strategical view of it please if needed).
More agressivity (kosumi tsuke) means the opponent must choose (his choice) between giving up a part of the group to go out (but it is a mess) OR making local profit but being isolated from the rest of the game. As escaping in the center is often a valid move on a 19*19 goban it is worth considering.
The Yoshinori option seems peacefull but honte, as it allows (force in reality = you choose) the escape but keeps the group weak with only one eye and no profit.
guile: As this collection is about basics maybe some comment is needed for the reader. You definetely can capture the weak group (the left part of it) in a somehow ok-ish way. But with the offered solution you CHOOSE (wisely) an other option : to make profit by strengthening your own weak right corner's AND preventing opponent local profit AND creating a weak group which gives you potential profit later. You essentially created a good target, which is efficient in Tuban. Potential is key here : FUTURE profit matters more than IMMEDIATE profit.
posetcay: Can you please write the sequence of how to capture the left part of the group? Because I can't see any way. If it was possible to capture, that would be the correct way to play because not only is it worth a lot of points but it also weakens opponent's group.
I am not sure which "marked stones"?