Roberts vs Casey 6-13
White answers at . He is rightly assuming, that this hits a weak spot, but is too hasty. The game has a theme now: Will Black find a good moment to cut at a?
To begin with, he could cut immediately. White is separated into 3 stones whereas black is at least loosely connected to one group. This looks fine to me!
After White might even turn back to defend at . provides some aji to be used later.
The reader might consider the cut /defense at (a in the initial diagram) for any of the next moves himself!