In this game - against a
knowledgeable opponent - we see black carrying out, in great style, a K-side pawn advance similar to the famous "Mar del Plata" attack from the King's Indian (I wonder if black plays this opening too).
1.d4
Nf6
2.c4
d6
3.Nc3
Nbd7
The Old Indian Defence (with -Be7) has a reputation for passivity compared to the King's Indian (with -Bg7). However, in amateur play between strongish opponents, more important might be the subtleties and nuances of the various plans for white and black ... and how much more one of the players knows than the other how to play the set-up that finally appears on the board. Where the players are less strong, often the game dissolves into tactics and the choice of opening turns out to be of little relevance anyway.
4.e4
There's something to be said for the system 4 Nf3 e5 5 Bg5 Be7 6 e3, continuing with Qc2/Bd3. That way, white ducks out of some of the problems that can arise in the e4 lines from black's ideas, later on, of: (i) -e5/-exd4 and (ii) -Nf8/-Ng6/-Nf4. Also, it definitely rules out the King's-Indian because of 5 Bg5 g6? 6 dxe5 dxe5 6 Nxe5 Nxe5 7 Qxd8+ Kxd8 8 Bxf6+
4...e5
5.Nf3
c6
Black could go into the King's Indian now, or on the next move, by -g6/-Bg7 but he will have his QN on a poorish square compared to the modern -Nc6 way of playing it
6.Be2
Be7
7.h3
There is no need for this move, which is necessary in the King's Indian, because black's Be7 is not contributing to the attack on white's Pd4. Thus, 7 0-0 0-0 8 Qc2 Re8 9 Be3 Ng4 can be met by simply Bd2 and h3 ... against other black 9th moves, white can play for d5 and Nd2 or Ne1/Nd3 when he has saved a tempo and avoided weakening his K-side
7...0-0
8.0-0
Re8
9.Qc2
Bf8
An alternative was the plan of -Qc7/-Nf8/-Ng6 eying up the -Nf4 move which would be all the stronger owing to 7 h3
10.Be3
Diagram
10...h6
11.Rfd1
White is playing all the right moves now ... in time, he will aim for Rab1/b4 with or without the advance d4-d5
11...Qe7
Now we see the reason for black's 10th move ... he threatens -exd4 picking up the Pe4 without losing his Ph7 to Bd3 in the process. However, this is an unusual placement for the queen and might be too great a price to pay for forcing white's next
12.d5
Most times, the player who releases tension by exchanging pawns or pushing past suffers for it. Black's position is easier to play now
12...c5
This is a double-edged move which might be giving more than it gets in return
13.a3
This looks like a mistake ... he should move his Nf3. Best seems 13 Ne1 heading for d3. Then the a3/b4 plan could meet black's -b6 defence by a3-a4-a5 because cxb4 would allow Nxb4/Nc6
13...Nh5
14.Qd2
By g3/Bf1 white would retain his advantage better ... he could then have continued his plan to open lines on the Q-side for his pieces
14...Qf6
15.b4
b6
16.b5
White plans a4/a5 but the slight slowing of his attack gives black a chance to strike back on the other side - also, black can stop worrying about Nb5 now
16...Nf4
17.Bxf4
This is a misjudgement. White brings the Bf8 back to life and gives black a spearhead for his K-side pawn storm
17...exf4
18.a4
g5
See how well black's queen is placed now
19.a5
Bg7
This bishop, unopposed, will become the most effective piece on the board
20.Ra3
Qg6
21.Nh2
Rb8
22.f3
h5
Black has the advantage now ... but he still needs to play patiently in order to time his -g4 break for optimum effect
23.Rda1
Bd4+
24.Kh1
Diagram
24...Qg7
Black shows his class with a clever move ... he judges (and that's what it is - not a calculation) that he didn't have time right now for the obvious -Kg7/-Rh8 plan and decides to apply a little prophylaxis against a possible white break through on the a-file
25.R1a2
Ne5
26.Nb1
Be3
Now the weakness of the Pf4 will not hinder the -g4 plan
27.Qd1
Qg6
28.Nd2
Kg7
29.Ndf1
Bd4
30.axb6
axb6
31.Ra7
No better is 31 Ra8 Rxa8 32 Rxa8 g4! and -Rh8
31...Bd7
32.Nd2
g4
The availability of -Rh8 makes the key move possible
33.fxg4
hxg4
34.Rxd7
White finds the best move ... but it's insufficient to stop black's breakthrough
34...gxh3!
35.gxh3
Nxd7
36.Bg4
Nf6
Black could have taken the file for himself now with 36 -Ra8
37.Bf5
Qh6
38.Ndf3
Be3
38 -Nxe4 grabbing the pawn was stronger but one can understand black's attachment to the hero-bishop
39.Rg2+
Kf8
40.Ng5
Ra8
41.Ng4
Nxg4
42.Qxg4
Ra1+
43.Kh2
f3
Decisive
44.Qxf3
Bxg5
0-1