The theory behind the Chinese is that black stakes out more territory than he can reasonably get, leaving white with two alternatives:
1) White can invade, and black will attack the invaders and try to make territory while chasing.
2) White can reduce, conceding some territory to black, and later use the influence of those stones.
[Actually, there is theoretically a third alternative for white: ignoring black and concentrating on building your own side of the board. For some reason this is hardly ever played. It may be because it is inferior, or because it simply lacks fighting spirit. I do not know. I suspect that it is a little of both.]
If you choose invasions as your counter technique, the biggest problem be that you cannot easily invade the whole right side of the board with one invasion, and therefore you have to make sure that you do not have multiple attackable invasions at the same time. ( Remember the proverb that says never have more than one weak group at a time? It applies in spades here because your weak groups will be surrounded from their infancy. ) You have to secure life for one invasion before you begin another.
If you choose reduction as the counter technique, you again have a sub-choice: will the reducing stones be used to make a moyo and beat black in a big territory vs big territory game, or will they be used as influence to beat black in a bloody central board melee?
A hybrid strategy is also possible: to reduce on part of the board and to invade on another.
Regardless of how you do it - reduction or invasion or hybrid - it must be remembered that the board is big and that there will almost certainly be several separate conflicts going on. This means that you have to maintain a whole-board view and coordinate your actions in each of those conflicts.
So much for theory. Let's look at practice.
You played a hybrid.
* You reduced the lower right with N4, and later tried to use that strength for a moyo with P6/P7 and D6/D8.
* You invaded in the upper right, he attacked, and tried to make territory with moves like R15 and O16.
* You invaded with around M17 with moves 40-44.
As expected, you had multiple conflicts - 2 invasions, 1 reduction - and they had to be coordinated. It is in the coordination that your game went bad.
You had a semi-stable invasion around R11-R14. ( I say "semi-" because he attacked with 35 and 37, and you defended with only 36 and then tenukied. The tenuki was not necessarily a bad move, but it did mean that you owed a move over there, and you thus could not start a second invasion until your first was secure )
Near that semi-stable invasion, you started another invasion at M17. You did not wait until your first invasion was safe. He eventually hacked through between them at N14. As a result one of those groups died.
Your second coordination problem occurred soon after when your R11/R14 group had become notably weak, and you tried to make a moyo with P6 and P7. That in itself was ok, but it did not mesh with the defense of your weak group. He played N9, a dual purpose move. It locks in your weak invaders, and it slides across the top of your impending moyo to reduce it. This turned into your second loss as you tried to seal the top of your moyo, but he had gotten there first with N9 and not surprisingly won the ensuing fight. This second loss of a group precipitated your quite reasonable resignation.
In each instance - N14 and N9 - you built groups with conflicting goals such that he was able to make a move that threatened two things simultaneously.
Work on maintaining a whole-board view and coordinating your groups and you'll beat him next time.
