I might classify this next game as an exercise. Here is the challenge, but maybe just for me! I was reading an article (more of an product offer) from ChessBase about improving calculation ( https://en.chessbase.com/post/how-to-improve-your-calculation). The game introduced in the introductory writing is posted below.
The "exercise' might be more of a "help me!" call to identify a line of rationale for the comment after the 33rd move (33.d4!). The annotator writes: "...neither rook of queen can take on d4". Why not?
I do not doubt the annotator but like you probably, I will calculate these type of moves especially when there is an assumed understanding about any checks, captures or threats. Well, it is an article on calculation!
I hoped someone here might "see" the answer readily, but I will be setting up a board today to observe and calculate til I solve this mystery. Feel free to offer any thoughts!!
A Guide to Chess Improvement section 4-4, The Three Types of Chess Vision
As Dan writes about board and tactical vision, he pulls an exercise from the book, "Genius in Chess" by GM Jonathan Levitt. Time yourself to find as quickly as possible:
1) How many legal moves does White have; and
2) How many checkmates in one move does White have?
Your answer should reflect two numbers. For example your answer would be in the form of "40 legal moves and 7 of these are checkmate".
Remember, White to play - how many legal moves and how many checkmates?