I have just added two books to my collection:
Chatterjee, Sangit; Huiren Yang. Whole Board Living Tesuji: Problems Drawn From Real-Life Games.
Sung-Rae, Kim. 21st Century New Openings.
Whole Board Living Tesuji:
This book is clearly meant for dan-level players who have a lot of experience with the game. I have not read any other "whole board tesuji" books, but here is what I take it to mean. One player is in a situation where the normal move will give their opponent a huge global advantage (securing a weak group, being able to attack your own weak group, invading and stealing a lot of point). While there are many local replies, the one in question addresses the local and global problems. As such, this book is useful to different ranked players in different ways. A beginning player (DDK) will not get very much from the book at all, besides examples of good plays. Given the very specific nature of each problem, this is not going to lead to anything they can definitely grasp on to, but will give them an example of moves they would never think of, or would never understand the value of if they did happen to play it. An intermediate player (SDK) will get a little more out of this, because they have the background to pick for themselves the conventional (and wrong moves), and this book will be full of ways for them to see how the conventional move is not the best. If given the problems without context, they would likely pick the wrong move each time, and even in context there is not a great chance that they will pick the proper move, and even if they do, it is probably more luck/instinct than the reading that is required to find such moves when you are not sure there is a tesuji answer (ie their own games). However, the example that they find will be very useful for shaping how they see whole board positions, finding the key areas, and expanding their base of moves to consider. An advanced player (Dan Level) will have a chance at solving the problems and finding the right answer. As a 1-2d I am able to figure out some of the problems on my own, though the reading can get to be much (I acknowledge myself as a horribly lazy reader though). I feel like even players up to 9d could get some real benefit from this book, though some of the problems are surely quite easy for them to solve.
21st Century New Openings:
I love the concept of this book, and its hopefully forthcoming volumes. Every three years, the author is going to look for new moves and new opening trends that crop up in professional play, and then analyse the many variations that stem from them, compare with older methods, and give real game examples of the new play. This includes simple joseki, to new joseki in older fuseki patterns, and even novel fuseki. The book is clearly targeted at serious players who are trying to remain competitive in high level play. It assumes a good foundation of past joseki and fuseki knowledge, as well as being written in a thoroughly academic style. I would have loved this book when I was 4k, and probably been able to benefit from it somewhat, but as the author claims, this book is most useful for people looking to become professionals. While the volume I have is from 2006, hopefully there have been or will be new volumes coming out, given the fast-changing nature of these joseki and patterns in modern time.