Space vs Material

1. When the opponent's pieces are cramped. If a pawn sacrifice gives you a massive space advantage that restricts all the opponent's pieces, it's usually worth it. Cramped pieces can't defend effectively.
2. When space supports an attack. Space near the opponent's king enables piece manoeuvres that lead to mating attacks.
3. When the space advantage is permanent. If the opponent can't easily challenge your space advantage with pawn breaks, it's more valuable.

1. When the opponent can break through. If a pawn break can equalize the space, the material is more important.
2. In endgames. Space advantage diminishes as pieces are traded, material advantage grows.
3. When the space doesn't restrict key pieces. Having more space on one side while the opponent operates freely on the other isn't a real advantage.
4. When the extra material is useful. An extra pawn near the opponent's king may be more valuable than general space.

• Count controlled squares: Who controls more squares in the centre and in the opponent's half?
• Assess piece mobility: How many useful squares does each piece have?
• Check pawn breaks: Can the opponent challenge your space with a pawn break? If yes, the space advantage is temporary.
• Assess the endgame: Will the space advantage persist into the endgame, or will it disappear with pawn trades?

The King's Indian Defence is a classic space-vs-material opening: White gets a space advantage; Black accepts the cramped position and seeks counterplay. The Maróczy Bind is another example: White's c4+e4 pawns create lasting space advantage. AlphaZero's games often feature spectacular space advantages created by early pawn advances. See Chess Imbalances.