Beside the literal meanings Taisha = "large diagonal" - I read "great slant" in the Almanac - and Nadare = "avalanche", their complexness means, that, often,you don't know what the next move will bring: sente or gote ending?; influence or corner for yourself?; a tactical move which you did not expect, might inverse your global planning (e.g. "I would like to end in sente, and some own influence to the right would be nice"), because you are tactically forced to accept an unwanted result.

These Josekis are especially dangerous, if you know them only halfway. Both can be quite long, fill a quarter of the board and dominate the rest of it.

If I can not control the outcome of such an important factor for the game result - because I have only basic knowledge of these Josekis - then I play them only for fun & training reasons. It is fun to play several games in succession with the same person, always chosing the taisha - or offering the possibility for it - then play it and learn.

In important games, the choice of Josekis can also be a statement. When Go Seigen had just invented the inward turn? of the large avalanche, most players would avoid it, but Kitani chose to play it twice in one game vs. Go (if I recall correctly). They were friends yet/and it means "I am not afraid of any challenge". tderz