Discovered - chess tactic: uncovering attacks
Discovered
Definition
In chess, “discovered” refers to a tactic where moving one piece reveals (or “uncovers”) an attack from a second piece that was previously blocked. The most common forms are the discovered attack and the discovered check. When the moving piece also gives check at the same time, the result is a “double check.”
How it is used in chess
Players employ discovered tactics to gain time, win material, or deliver checkmate. Because the opponent must address the newly revealed threat, the moving piece often gets a “free” tempo to attack something else (for example, a fork or capture). Discovered ideas are especially powerful for long-range pieces (bishops, rooks, and queens) along open files or diagonals.
Key types
- Discovered attack: Move a front piece to uncover an attack by a back piece (e.g., a rook on an open file or a bishop on a long diagonal).
- Discovered check: Move a piece to reveal a check from a hidden piece. The opponent must answer the check, giving you tempo.
- Double check: The moving piece gives check and also reveals a second check from the hidden piece. Only a king move can legally meet a double check, which often makes it a decisive tactic.
- Discovered mate: A discovered check that ends in checkmate, sometimes via double check or an unavoidable mating net.
- Windmill (seesaw): A repeating sequence of discovered checks where a rook or bishop alternates giving check, collecting material in between checks.
Strategic significance
- Geometry and alignment: Discovered ideas thrive when two of your pieces are aligned with an enemy target (king, queen, or major piece) and one is blocking the other.
- Tempo and initiative: A discovered check forces an immediate response, letting the moving piece create an additional threat with tempo.
- Pins and x-rays: Pins can both enable and neutralize discoveries. A pinned front piece might be unable to move, but an x-ray against the pinned piece can also set up a discovery against the pinning piece.
- Open positions: The more open the board (fewer pawns), the more dangerous long diagonals and files become for discovered tactics.
Examples you can visualize
-
File-based discovered attack (winning a queen):
White: king g1; rook d1; bishop d2; queen c2. Black: king g8; queen d8; rook e8. It’s White to move. 1. Bc3! removes the bishop from the d-file and uncovers Rd1–d8 against Black’s queen. If 1...Qe7, then 2. Re1 wins the pinned rook on e8. If 1...Qxd1+ 2. Qxd1, White trades favorably having forced concessions.
-
Diagonal discovered check:
White: king g1; rook e1; bishop c4; queen h5. Black: king g8; knight f6; pawns g7, h7. White plays 1. Qxf7+! Kh8 (or 1...Kh8 forced) 2. Re8+! Qxe8 3. Qxe8+ Nxe8 4. Bf7. A more thematic line is 1. Qxf7+ Kh8 2. Re8+! Nxe8 3. Qg8# if Black’s back rank and dark squares are compromised. The idea is that Re8+ can be a discovered check when the bishop on c4 is aimed at g8, and the rook move simultaneously creates new threats.
-
Double check pattern:
Imagine a bishop on b2 and a rook on g1 pointing at Black’s king on g8, with a white knight on h6 blocking the rook. If White plays 1. Rxg7+!! (or 1. Qg8+ in other layouts), sometimes the move reveals a check from the bishop while the moving piece also checks—this is a double check. Since only a king move can reply, the defender’s options are severely limited, often leading to mate.
-
Windmill (seesaw) harvest:
Place a rook on the 7th rank checking the king, supported by a bishop on the long diagonal. The rook alternates between giving discovered check (by moving) and recapturing material, e.g., Rg7+! Kh8, Rg8+! Kxg8, Bc4+! and so on, regaining the rook with interest while the checks continue. This classic device can decide games outright.
How to spot and calculate discoveries
- Scan for lines where your rook, bishop, or queen is “parked behind” another piece aimed at a target.
- Ask, “If my front piece moves, what does the back piece attack?” Then search for front-piece moves that create a second threat (fork, check, or capture).
- Consider forcing moves: checks and threats that limit the opponent’s replies help a discovery succeed.
- Beware of pins: a pinned front piece might not be free to move. Break the pin or convert it to your advantage before attempting a discovery.
Defensive resources
- Step out of the line: Move the king or high-value piece off the file/diagonal to defuse the discovered attack.
- Interpose or capture: Block the line with an interposing piece or capture the attacking unit that’s about to be revealed.
- Counter-threats: Create your own forcing move (check or mate threat) to distract and neutralize the discovery.
- Prophylaxis: In advance, avoid aligning valuable pieces with enemy long-range pieces when they can be uncovered.
Interesting facts and anecdotes
- Double check uniqueness: In a double check, only king moves are legal. You cannot parry both checks by blocking or capturing just one attacker.
- En passant discoveries: Rarely, an en passant capture can open a file for a discovered check. For example, a pawn on e5 capturing d6 en passant can expose a rook on e1 to check along the e-file.
- Puzzle favorite: Discovered tactics are staples of tactics training because they combine forcing moves and geometry, sharpening calculation and pattern recognition.
- Windmill brilliancies: Many famous brilliancies feature windmill sequences where repeated discovered checks pick up massive material before delivering mate.
Related terms
Practice tip
Set up positions in your games where two of your pieces align against a target with one in front of the other. Before each move, ask yourself: “If this front piece moves, what do I discover?” That single question will help you spot decisive tactics you might otherwise miss.