Unexpected joseki ending

The last move here seems a bit random. Can someone explain why this is the choice?


White needs to protect against the push and cut (B: P15, W: O15, B: O14). Two simple ways to do that would be to connect at P15, or make a bamboo joint with O14. However, N13 expands the influence further, which is probably what white is aiming for if they choose this joseki, while also protecting the cut.

It does leave a little more weakness than other options, and in some positions black may be able to gain an extra forcing move or two later. But it could also contribute to making eyeshape at some point, so it’s a balance.

As always with joseki it may depend quite sensitively on what the surrounding stones are like and white wants to gain from it.