4-4 point low approach one-space low pincer, high double approach
The high double kakari of is played less often than the low one of White a. It also has fewer variations; rarely is anything played except the sequence to .
The quiet exchange of for is again joseki (see below for Black resists). Compared to the position with at a, the left side is more important. Black has interesting follow-up moves at b and c, places he would not dream of playing if White had the solid position with at a.
After black tenuki, the exchange of white d for black e is large, especially if the ladder at f favors white.
The great advantage for White of the high double kakari, is that Black can't now try to resist by playing here. White can march right through Black's position with to , and after , Black's position crumbles.
AndreEngels, Tapir