User blog comment:Rgetar/"Math football"/@comment-30004975-20171124032758/@comment-32213734-20171124234837

For example,

close close 0 to 1 close open close 0 to 1 close open open close 0 to 1 close open open open close 0 to 1 ...

It will be difficult to close move 0 to 1 (if it is not already closed), and Player 1 can freely move the object from 0 to 1 until this hole exists.