Own camp Rook

What do you move in figure. 1?

 

figure. 1

It is often said that you should put Rook on Enemy camp to attack.
However, putting Rook on your own camp (f, g, h, i line, in general) is effective occasionally.
Then, I moved R*5f (figure. 2).

figure. 2

In this case, R*5f aims to win by not attack but shutout the opponent's attack.
In some cases, shutout brings winning faster than attack as a result.
The game proceeded after figure.2, B-9c, S*5c, N*4a, Sx4b+, Gx4b, P-9f, P*4g, S-5g, G-4c, R-6h (figure. 3).
In figure. 3, the opponent resigned. It's because I was very dominant and the opponent had no chance of wining viewed from Dan holder in figure. 3.

figure. 3

Own camp Rook is high level technique.
So, if you knew this, it must be helpful for your improvement.