PJ step 2. the most small value (2) /baduk/

There are triangle marks. It means decided-territory.

Black will do like this and created 1 black cross.

White will do like this and created one third black cross. You already knew if only you read "the most small value (1)."
So, there exists two thirds black cross.
If it's black turn, there created 1 black cross. The numeral difference is one third.
Therefore, each turns earn one third and its value is two thirds.

Conclusion : Exists two third black cross. / Value is two thirds.

There is a convenient way.
Black will want to play elseway instead of sequence 2.
Of course it can!

But anyhow white do 2 sequence, then, black must do 3 sequence.
Because 3 sequence is bigger than two thirds.
And because reasonal white player thought that there is not bigger one.