Xiangqi End Game Technique #3;: Using King to control center file

Xiangqi End Game Technique #3:

Using King to control center file

Diagram 1

Red to move.

Diagram 1 shown a composed game. Now is Red's turn. 

In the surface, it seems that Red can play R1=5 to control the center file follows by P8=7 checkmate. However, Black has a trick to turn the situation if Red plays R1=5.

Let see how Black countrr attack!

Red R1=5 Black P3+1   K6+1   R5=4   K6=5   C5-6. Black canno n is able to capture Red chariot! Black sure win!

Since Red R1=5 is a weak move, then what is the best move for Red?

Red R1-7 is the correct move!

If Black R5=9 to capture Red chariot.... Red K6=5 Black R9-8   Red P8=7  checkmate! Diagram 2.

If Black K4=5, then Red would capture Black chariot R1=5, and sure win.

There are other possible variation for Black, i am sure you can figure out how do Red win the game!

Diagram 2