Getting ahead with a one-point jump
When Black is not strong in this part of the board, his running group is most probably under attack. The basic move for defense is a one-point jump. Thus getting ahead with a one-point jump can be recommended.
In this nadare variation, (rather than a) tries to get well ahead of Black.
This continuation is nearly forced. White has better influence than would be gained with White a in the previous diagram, and Black cannot yet cut at b.