Quick answer
Four Rook Endgame Principles is an endgame technique: Lucena bridge-building. Work from the first evidence position for Four Rook Endgame Principles, and begin by testing Kc5.
Begin from Kc5 in 7k/4r3/B1K5/8/8/8/8/R7 w - - 3 3. Count the material, king routes, promotion squares and reserve tempi before applying a theoretical rule. The evidence answer is: Four Rook Endgame Principles: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kc5.
In the Four Rook Endgame Principles example, notice: side White; pieces Black king h8, Black rook e7, White bishop a6, White king c6, White rook a1; legal first moves Bb7, Bc8, Bb5, Bc4, Bd3, Be2, Bf1, Kd6. Read those squares as a snapshot of this single board, not as a standing rule you can copy into every game.
Material and result question
The first evidence board tests Lucena bridge-building; the second board tests Lucena bridge-building. Sequence A is direct FEN setup. Sequence B is direct FEN setup. Compare them only after setting both FENs. Hub vocabulary: Chess Wiki · Endgames hub. Then compare Material Values with Active King In Rook Endings, Queen Versus Pawn, Queen Versus Rook around the side-to-move tempo.
The two inventories make the distinction concrete. A contains side White; pieces Black king h8, Black rook e7, White bishop a6, White king c6, White rook a1; legal first moves Bb7, Bc8, Bb5, Bc4, Bd3, Be2, Bf1, Kd6; B contains side Black; pieces Black king h8, White king b7, White pawn c7, Black rook h5, White rook h1; legal first moves Kh7, Kg7, Kg8, Rh6, Rh7, Rh4, Rh3, Rh2. Compare the side to move before comparing the labels in the context of a reserve pawn move.
Topic dossier for this page and board pair r1:7k | r2:4r3 | r3:B1K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:R7 / r1:7k | r2:1KP5 | r3:8 | r4:7r | r5:8 | r6:8 | r7:8 | r8:7R: start with the side-to-move tempo; then test a reserve pawn move; keep the active rook before the pawn push separate from the conversion move order; use an outside passer used as a decoy as the transfer check; and reserve the defender's only active counterplay for the exception.
Conversion or defense plan
On the first board, calculate Kc5 after Kc5 and write down the opponent's best reply around the side-to-move tempo. On the second board, calculate Kh7 after Kh7 and check a reserve pawn move. Separate the practical conversion question from the result question; side to move and one checking distance can change the conclusion. In this case the useful condition is the defender's only active counterplay.
Key claim: Four Rook Endgame Principles is illustrated here by Lucena bridge-building; the first concrete test is Kc5. The board anchor is 7k/4r3/B1K5/8/8/8/8/R7; the example is intentionally narrower than the topic label and should not be generalised without checking the surrounding position..
Practical boundary: To answer “What exact king, pawn, and move-order conditions decide four rook endgame principles, and how should each side play them?”, compare the recorded setup with Kh7 and the opponent's reply. The decision is useful only when the stated condition survives that concrete test on board 7k/1KP5/8/7r/8/8/8/7R. The evidence records No tablebase outcome is asserted by this generated record; verify the exact FEN before publication and the second board signature r1:7k | r2:1KP5 | r3:8 | r4:7r | r5:8 | r6:8 | r7:8 | r8:7R. The false-positive test is whether the active rook before the pawn push appears without the conversion move order, so the conclusion is useful only when the stated condition survives that concrete test.
Evidence positions
example-1: Lucena bridge-building
Show answer
Four Rook Endgame Principles: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kc5.
Why this position is here: Four Rook Endgame Principles is represented by Lucena bridge-building. This is a direct FEN setup with board anchor 7k/4r3/B1K5/8/8/8/8/R7; no opening history is inferred from the diagram.
FEN: 7k/4r3/B1K5/8/8/8/8/R7 w - - 3 3
Question: What is the first concrete decision in this four rook endgame principles position?
Answer cue: Four Rook Endgame Principles: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kc5. The first candidate to test is Kc5. Replay Kc5 on board anchor 7k/4r3/B1K5/8/8/8/8/R7 and write down what changes after it.
Evidence boundary: No tablebase outcome is asserted by this generated record; verify the exact FEN before publication.
example-2: Lucena bridge-building
Show answer
Four Rook Endgame Principles: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kh7.
Why this position is here: Four Rook Endgame Principles is represented by Lucena bridge-building. This is a direct FEN setup with board anchor 7k/1KP5/8/7r/8/8/8/7R; no opening history is inferred from the diagram.
FEN: 7k/1KP5/8/7r/8/8/8/7R b - - 3 2
Question: What is the first concrete decision in this four rook endgame principles position?
Answer cue: Four Rook Endgame Principles: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kh7. The first candidate to test is Kh7. Replay Kh7 on board anchor 7k/1KP5/8/7r/8/8/8/7R and write down what changes after it.
Evidence boundary: No tablebase outcome is asserted by this generated record; verify the exact FEN before publication.
example-3: Lucena bridge-building
Show answer
Four Rook Endgame Principles: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kxh7.
Why this position is here: Four Rook Endgame Principles is represented by Lucena bridge-building. This is a direct FEN setup with board anchor 6k1/1KP2r1R/8/8/8/8/8/8; no opening history is inferred from the diagram.
FEN: 6k1/1KP2r1R/8/8/8/8/8/8 b - - 5 3
Question: What is the first concrete decision in this four rook endgame principles position?
Answer cue: Four Rook Endgame Principles: use the king's shelter and a checking-distance bridge before advancing the pawn. Candidate line: Kxh7. The first candidate to test is Kxh7. Replay Kxh7 on board anchor 6k1/1KP2r1R/8/8/8/8/8/8 and write down what changes after it.
Evidence boundary: No tablebase outcome is asserted by this generated record; verify the exact FEN before publication.
Reading the line
Read the first example (id example-1) as a complete record: continuation Kc5, source tablebase. This is a direct FEN setup with board anchor 7k/4r3/B1K5/8/8/8/8/R7; no opening history is inferred from the diagram. If A does not expose Lucena bridge-building, correct the evidence before relying on the prose.
Read the second example (id example-2) separately: continuation Kh7, source tablebase. Its feature is Lucena bridge-building; inventory side Black; pieces Black king h8, White king b7, White pawn c7, Black rook h5, White rook h1; legal first moves Kh7, Kg7, Kg8, Rh6, Rh7, Rh4, Rh3, Rh2. Compare what changes between Kc5 and Kh7.
Boundary cases
The main mistake to avoid with Four Rook Endgame Principles is applying a remembered endgame rule while ignoring side to move, king placement or an unverified result. In A, the missing condition must be located in r1:7k | r2:4r3 | r3:B1K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:R7 after Kc5; in B, test it against r1:7k | r2:1KP5 | r3:8 | r4:7r | r5:8 | r6:8 | r7:8 | r8:7R after Kh7.
For Four Rook Endgame Principles, the first board's evidence boundary (after Kc5) is No tablebase outcome is asserted by this generated record; verify the exact FEN before publication. The second board's evidence boundary for Four Rook Endgame Principles is No tablebase outcome is asserted by this generated record; verify the exact FEN before publication. If a trusted source or careful calculation changes the conclusion around an outside passer used as a decoy, update both the evidence record and this article.
Practice from a real game
play the position for both sides, record the critical tempo, and verify the exact FEN against the cited tablebase before publication. Start with A's side to move and r1:7k | r2:4r3 | r3:B1K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:R7; record two candidates, the reply to Kc5 and the correction. Repeat with B's side to move and r1:7k | r2:1KP5 | r3:8 | r4:7r | r5:8 | r6:8 | r7:8 | r8:7R; the changed board tests transfer rather than diagram memory.
After the drill, compare your notes with Active King In Rook Endings, Queen Versus Pawn, Queen Versus Rook through the conversion move order. Keep A's rejected alternative beside B's chosen line Kh7; this shows whether the conclusion survived a new board signature.
Sources and scope
Sources for Four Rook Endgame Principles: Syzygy tablebase verification reference, 1chess.online editorial scope. Source ids are tablebase, original-analysis. Primary evidence hook: tablebase. Comparisons and practice notes are editorial. Evidence revision: 2026-08-remediation-r2.
Scope note for board pair r1:7k | r2:4r3 | r3:B1K5 | r4:8 | r5:8 | r6:8 | r7:8 | r8:R7 / r1:7k | r2:1KP5 | r3:8 | r4:7r | r5:8 | r6:8 | r7:8 | r8:7R: this page does not claim that Kc5 is an engine principal variation, that an exact endgame result is verified when the evidence says it is not, or that a tool output replaces human calculation. The conclusion is limited to the recorded boundary and the exception the active rook before the pawn push.