--- title: "Diagonal in chess" url: "https://georgelichess.com/glossary/diagonal.md" canonical_url: "https://georgelichess.com/glossary/diagonal" last_updated: "2026-11-07" type: "reference" summary: "A diagonal is the slanting path a bishop travels, a straight run of squares of a single color from one edge of the board to a neighboring edge." related: ["https://georgelichess.com/glossary/bishop.md", "https://georgelichess.com/glossary/fianchetto.md", "https://georgelichess.com/glossary/battery.md", "https://georgelichess.com/glossary/pin.md", "https://georgelichess.com/glossary/skewer.md", "https://georgelichess.com/glossary/bad-bishop.md", "https://georgelichess.com/glossary/category/rules-notation.md", "https://georgelichess.com/glossary.md"] --- # Diagonal in chess > **For AI agents:** the complete index of GeorgeLiChess pages is [llms.txt](https://georgelichess.com/llms.txt). Every page is also served as markdown at its URL plus .md. A diagonal is the slanting path a bishop travels, a straight run of squares of a single color from one edge of the board to a neighboring edge. A diagonal is the slanting path a bishop travels, a straight run of squares of a single color from one edge of the board to a neighboring edge, also used by the queen and by a pawn when it captures. Every diagonal consists of squares of one color only. A bishop therefore stays on its diagonals and never leaves its [color complex](https://georgelichess.com/glossary/color-complex.md). The long diagonals, a1 to h8 and h1 to a8, are the longest with eight squares each, and they pass through the center. Diagonals are central to strategy. A fianchettoed bishop on g2 or b2 aims down the long diagonal at the enemy king or queenside. Opening a diagonal toward the king, with a pawn exchange, is a normal way to start an attack. The queen also moves along diagonals, so a [battery](https://georgelichess.com/glossary/battery.md) of queen and bishop on one diagonal is a classic attacking setup. Pawns relate to diagonals too. A pawn captures one square diagonally forward, which is why [pawn chains](https://georgelichess.com/glossary/pawn-chain.md) point along diagonals and why you attack a chain at its base. Typical mistakes: ignoring a long diagonal that has quietly opened toward your king, or blocking your own bishop with pawns on its color. If the bishop is hemmed in by its own pawns, it becomes a [bad bishop](https://georgelichess.com/glossary/bad-bishop.md). A tip for calculation: when you consider a move, trace the diagonals leaving its target square. Many tactics, such as [skewers](https://georgelichess.com/glossary/skewer.md), pins and [discovered attacks](https://georgelichess.com/glossary/discovered-attack.md), run along a single diagonal that a quick look would have shown. It sits close to [Fianchetto](https://georgelichess.com/glossary/fianchetto.md). A fianchetto is the setup where a bishop sits on b2, g2, b7 or g7 behind a pawn that has moved one square, so that it eyes the long diagonal from a distance. Knowing "Diagonal" is the easy part; what to practice next depends on your rating, and the [improvement plans by rating band](https://georgelichess.com/improve.md) list the habits worth building at each level. ## Related terms - [Bishop](https://georgelichess.com/glossary/bishop.md) - [Fianchetto](https://georgelichess.com/glossary/fianchetto.md) - [Battery](https://georgelichess.com/glossary/battery.md) - [Pin](https://georgelichess.com/glossary/pin.md) - [Skewer](https://georgelichess.com/glossary/skewer.md) - [Bad bishop](https://georgelichess.com/glossary/bad-bishop.md) ## Guides that go further - [How to choose a chess coach](https://georgelichess.com/how-to-choose-a-chess-coach.md): What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid. - [How much does chess coaching cost?](https://georgelichess.com/chess-coaching-cost.md): Published rates for private, group and subscription chess coaching, with the source and the date of each. - [The first lesson](https://georgelichess.com/book/first-lesson.md): A game review, a read on your level and a written study plan from George Li. ## Sources - FIDE Laws of Chess (taking effect from 1 January 2023) (Article 2.4), read 2026-10-21: https://handbook.fide.com/chapter/E012023 - FIDE Laws of Chess (taking effect from 1 January 2023) (Articles 3.2 and 3.4), read 2026-10-21: https://handbook.fide.com/chapter/E012023 - FIDE Laws of Chess (taking effect from 1 January 2023) (Article 3.7.3), read 2026-10-21: https://handbook.fide.com/chapter/E012023 [Book your first lesson](https://georgelichess.com/book.md) and George Li reviews your games and builds a study plan around them. Questions about lessons: write to hello@georgelichess.com. ## Related - [Bishop in chess](https://georgelichess.com/glossary/bishop.md) - [Fianchetto in chess](https://georgelichess.com/glossary/fianchetto.md) - [Battery in chess](https://georgelichess.com/glossary/battery.md) - [Pin in chess](https://georgelichess.com/glossary/pin.md) - [Skewer in chess](https://georgelichess.com/glossary/skewer.md) - [Bad bishop in chess](https://georgelichess.com/glossary/bad-bishop.md) - [Chess terms: Rules, notation and equipment](https://georgelichess.com/glossary/category/rules-notation.md) - [Chess terms glossary: plain definitions](https://georgelichess.com/glossary.md)