Before komi go it was generally considered that this type of opening was too simple from White's point of view - and that therefore White should challenge Black before is played. But it is seen in contemporary Go (for example Kato Masao-Cho Chikun 1988 Honinbo League).
Clearly enough, there are two types of ryojimari positions: those arising from parallel openings, and those such as the example arising from diagonal openings. In either case there is a superficial simplicity in the opening, because it is joseki-less. These openings, however, when played by pros, tend to make up for that because the fighting that arises becomes a technical exercise in middlegame joseki.
One can therefore break down the study of these openings to some extent:
- ryojimari sides, i.e. side patterns featuring two enclosures;
- use of middlegame joseki for reduction, invasion and probes around enclosures.