A classic problem endgame: Queen and pawns vs two rooks and pawns.
White: Ghost of a Duke (ca. 1700), Black: moonbus (ca. 1960); notes by moonbus.
1... c6 2. d4 d5 3. exd5 cxd5 4. Ng1f3
Caro-Kann Exchange Variation, designated B13. (4. c4 would initiate the Panov-Botvinnik Attack variation.)
4... Ng8f6 5. Nb1c3 Bc8g4
Black has several tasks to accomplish in order to equalize in this variation: one is to get the QB either well-posted or traded off, otherwise it will be trapped behind the Black center after … e6, which is inevitable.
Black's next task is to deny White control of the h2-b8 diagonal and thereby control of the black squares in the centre. It is also imperative for Black to prevent the encroachment of the White knight to either e5 or c5.
12. Bc1f4 Qd7c7 13. Bf4xd6 Qc7xd6
Positional assessment of the opening: Black has equalized, has good development, even control of the black and white squares, a solid center, and a safe haven for the king; White's control of the center is slightly less firm, and he must now decide where to place the rooks.
Masters (I do not pretend to be one) would probably put the rook on d1, overprotecting the d-pawn.
14... Ra8c8 15. Ra1c1 O-O 16. Re1e2
Black was threatening to double the rooks on the c-file and then advance the b-pawn to drive the White knight away; a typical Caro-Kann attack pattern. White understandably wants to re-inforce the weak c-pawn, but this move will prove to be a lost tempo. The rook belongs on d1 to shore up the d4-pawn.
Black immediately exploits the awkward placement of the White rooks and picks up a free pawn.
17. Nc3d1 Qb6xd4 18. c3 Qd4b6 19. Rc1c2 Nf6e4
This knight is now the most powerful piece on the board and cripples White's maneuverability.