zanzibar: Let's start with this game, which isn't on <CG>, although it can be found on ICOfY (wo Event/Site) and chess-db.com:
[Event 'HUN-ChT1B Charousek 0001'] [Site '?']
[White 'Reiss, Tibor']
[Black 'Imecs, Laszlo']
1. d4 d6 2. e4 Nf6 3. Nc3 c6 4. Nf3 Qa5 5. Bd2 Qc7 6. e5 dxe5 7. dxe5 Ng4 8. Bf4 Nd7 9. Qd2 Ngxe5 10. Nxe5 Nxe5 11. O-O-O Be6 12. Nb5 Qb8 13. Nd4 Bg4 14. f3 Bd7 15. Nb3 Bf5 16. Nc5 f6 17. g4 Bc8 18. Qd8+ Kf7 19. Bc4+ e6 20. Kb1 b5 21. Nd7 Qb7 22. Bxe6+ Kxe6 23. Qe8+ 1-0
First, it's a little confusing what kind of opening we have here. According to chess-db.com, this is a Rat Defense / Pillsbury Defense, which I think just means 1.d4 d6.
But SCID recognizes it as a transposition into a Pirc Czech (B07o - 1.e4 d6 2.d4 Nf6 3.Nc3 c6 4.Nf3).
Using Opening Explorer, 4...Qa5 is only seen 17 times (58.8% / 23.5% / 17.6% ). Of course the engines don't like this position for Black.
The opening is worth study for understanding the mistakes both sides make. It is difficult to actually realize the advantages which the engine assigns long before material can be won.
I'll defer such discussion for the moment, and present a simple little puzzle from the end of the game here:
(Pre-move: 21.Nc5-d7 Qb8-b7)