Blitz Rating List — IJCCRL Arena Series — Original UCI Track

Official result

Audit controls

• Audit verdict: AUDIT PASS.
• Match: IJCCRL Arena Series 2026 — Original UCI Track — Semifinal SF-M1 — Stockfish vs Alexandria.
• Format: Blitz 5+2, fixed mirrored match.
• Games: 50/50 closed.
• Scheduler state: openingIndex 50 and pending null.
• Colour balance: exact 25 White and 25 Black games per engine.
• Mirrored structure: 25/25 UHO opening units closed.
• Pair ratio: 0.
• Opening authority: UHO_2024_8mvs_big_+100_+119.pgn, lines #1–#25.
• PGN/results/scheduler/watchdog consistency: verified.
• Tiebreak required: no.
• Official semifinal decision: Stockfish advances to the final.

Result structure

• PGN result distribution: 36 wins for White, 14 draws and 0 wins for Black.
• Colour score: White 43.0/50, Black 7.0/50.
• Stockfish by colour: 24.0/25 as White and 6.0/25 as Black.
• Alexandria by colour: 19.0/25 as White and 1.0/25 as Black.
• Mirrored-unit distribution: 11 units won by Stockfish, 1 unit won by Alexandria and 13 units split 1.0–1.0.
• No incomplete mirrored unit was found.

Technical notes

• Termination distribution: 36 checkmates, 6 threefold repetitions, 4 stalemates, 2 games by the 50-move rule and 2 insufficient-material results.
• Total recorded TB hits: 10,373,896.
• Telemetry note: TB hits are recorded on the Stockfish side in the audited package; Alexandria reports 0 TB hits in the same records.
• This TB telemetry difference is documented as a reporting/configuration caveat and does not affect the match result.
• Official knockout record: Stockfish wins SF-M1 by 30.0–20.0 and reaches the final.

Official result

Audit controls

• Audit verdict: AUDIT PASS.
• Match: IJCCRL Arena Series 2026 — Original UCI Track — Semifinal SF-M2 — Reckless vs Obsidian.
• Format: Blitz 5+2, fixed mirrored match.
• Games: 50/50 closed.
• Scheduler state: openingIndex 50 and pending null.
• Colour balance: exact 25 White and 25 Black games per engine.
• Mirrored structure: 25/25 UHO opening units closed.
• Pair ratio: 0.
• PGN/results/scheduler consistency: verified.
• Tiebreak required: no.
• Official semifinal decision: Reckless advances to the final.

Result structure

• PGN result distribution: 39 wins for White, 11 draws and 0 wins for Black.
• Colour score: White 44.5/50, Black 5.5/50.
• Reckless by colour: 24.5/25 as White and 5.0/25 as Black.
• Obsidian by colour: 20.0/25 as White and 0.5/25 as Black.
• Mirrored-unit structure: 25 closed two-game opening units.
• No incomplete mirrored unit was found.

Technical notes

• Termination distribution: 39 checkmates, 4 insufficient-material results, 3 games by the 50-move rule, 3 threefold repetitions and 1 stalemate.
• No timeout, readyok-timeout, crash, illegal move, forfeit, disconnect or engine-error evidence was found in the audited package.
• Official knockout record: Reckless wins SF-M2 by 29.5–20.5 and reaches the final.
• The final pairing is therefore Stockfish dev-20260426-1a882efc vs Reckless 0.10.0-dev-8ba888c6.

Official final result

Final audit controls

• Audit verdict: AUDIT PASS.
• Match: IJCCRL Arena Series 2026 — Original UCI Track — Blitz 5+2 — Final — Stockfish vs Reckless.
• Format: fixed mirrored final.
• Games: 100/100 closed.
• Scheduler state: openingIndex 100 and pending null.
• Colour balance: exact 50 White and 50 Black games per engine.
• Mirrored structure: 50/50 UHO opening units closed.
• Pair ratio: 0.
• Time control: 300+2.
• PGN/results/scheduler consistency: verified.
• Tiebreak required: no.
• Official final decision: Stockfish is champion.

Result structure

• PGN result distribution: 83 wins for White, 17 draws and 0 wins for Black.
• Colour score: White 91.5/100, Black 8.5/100.
• Stockfish by colour: 48.5/50 as White and 7.0/50 as Black.
• Reckless by colour: 43.0/50 as White and 1.5/50 as Black.
• Mirrored-unit distribution: 37 units split 1.0–1.0, 12 units won by Stockfish 1.5–0.5 and 1 unit won by Reckless 1.5–0.5.
• No incomplete mirrored unit was found.

Technical notes

• Termination distribution: 83 checkmates, 7 threefold repetitions, 7 insufficient-material results, 2 games by the 50-move rule and 1 stalemate.
• Total recorded TB hits: 46,921,416.
• No timeout, readyok-timeout, forfeit, crash, illegal move, disconnect, engine error or exception evidence was found in the audited final package.
• ZIP package SHA256: 0915631152d8472610973a30086947fe01d3973d30ff3fd4a6dbb26dc2f5f029.
• games.pgn SHA256: 0750db18e6a62edbcdd6ac08d97b2b20dd578daf1773b249aaad13f5bd816cc0.
• Official champion: Stockfish dev-20260426-1a882efc.

Official result

Audit controls

• Audit verdict: AUDIT PASS.
• Match: IJCCRL Arena Series 2026 — Original UCI Track — R8M-M2 — Reckless vs Horsie.
• Format: Blitz 5+2, fixed mirrored match.
• Games: 50/50 closed.
• Scheduler state: openingIndex 50 and pending null.
• Colour balance: exact 25 White and 25 Black games per engine.
• Mirrored structure: 25/25 mirrored opening units closed.
• Pair ratio: 0.
• Opening authority: UHO_2024_8mvs_big_+100_+119.pgn, lines #1–#25.
• PGN/results/scheduler consistency: verified.

Result structure

• PGN result distribution: 35 wins for White, 15 draws and 0 wins for Black.
• Colour score: White 42.5/50, Black 7.5/50.
• Reckless by colour: 25.0/25 as White and 7.5/25 as Black.
• Horsie by colour: 17.5/25 as White and 0.0/25 as Black.
• Mirrored-unit distribution: 15 units won by Reckless 1.5–0.5 and 10 units split 1.0–1.0.
• No incomplete mirrored unit was found.

Technical notes

• Termination distribution: 35 checkmates, 9 games by the 50-move rule, 4 threefold repetitions and 2 insufficient-material results.
• Total recorded TB hits: 15,530,988.
• Telemetry note: recorded TB hits appear on the Reckless side; Horsie reports 0 TB hits in the audited records.
• This TB telemetry difference is documented as a reporting/configuration caveat and does not affect the match result.
• Official knockout record: Reckless advances over Horsie by 32.5–17.5.

Official result

Audit controls

• Audit verdict: AUDIT PASS after 50-game package normalization.
• Match: IJCCRL Arena Series 2026 — Original UCI Track — R8M-M3 — Obsidian vs RubiChess.
• Format: Blitz 5+2, fixed mirrored match.
• Games: 50/50 closed in the corrected publication package.
• Colour balance: exact 25 White and 25 Black games per engine.
• Pair ratio: 0.
• PGN/results/scheduler consistency: verified after removing the two surplus games.
• Tiebreak required: no.
• Official knockout record: Obsidian advances over RubiChess by 35.0–15.0.

Result structure

• PGN result distribution: 32 wins for White, 14 draws and 4 wins for Black.
• Colour score: White 39.0/50, Black 11.0/50.
• Obsidian by colour: 24.5/25 as White and 10.5/25 as Black.
• RubiChess by colour: 14.5/25 as White and 0.5/25 as Black.
• Termination distribution: 36 checkmates, 13 threefold repetitions and 1 game by the 50-move rule.
• Total recorded TB hits: 21,566,007.

Normalization note

• The downloaded raw package contained 52 games.
• The corrected audit package removes the two surplus games from the same final C25 opening block to restore the official 50-game contract.
• The corrected package keeps exact 25 White and 25 Black games per engine.
• The corrected score is Obsidian 35.0–15.0 RubiChess.
• The sporting decision is unchanged: Obsidian wins the match without tiebreak.

Official result

Audit controls

• Audit verdict: AUDIT PASS after mirrored 50-game correction.
• Match: IJCCRL Arena Series 2026 — Original UCI Track — R8M-M4 — Alexandria vs Clover.
• Format: Blitz 5+2, fixed mirrored match.
• Games: 50/50 closed in the corrected publication package.
• Colour balance: exact 25 White and 25 Black games per engine.
• Pair ratio: 0.
• PGN/results/scheduler consistency: verified after removing one surplus mirrored unit from the 52-game raw archive.
• Tiebreak required: no.
• Official knockout record: Alexandria advances over Clover by 27.5–22.5.

Result structure

• PGN result distribution: 33 wins for White, 17 draws and 0 wins for Black.
• Colour score: White 41.5/50, Black 8.5/50.
• Alexandria by colour: 22.0/25 as White and 5.5/25 as Black.
• Clover by colour: 19.5/25 as White and 3.0/25 as Black.
• All decisive games in the corrected PGN were won by White.
• The sporting decision is clear: Alexandria wins the match by 5 points without tiebreak.

Normalization note

• The downloaded raw package contained 52 games.
• A simple first-50 truncation was rejected because it produced Alexandria 26W / 24B and Clover 24W / 26B.
• The corrected audit package removes one complete mirrored unit so that both engines remain at 25 White and 25 Black games.
• The corrected score is Alexandria 27.5–22.5 Clover.
• Operational note for the next scripts: stop exactly at 50 games and avoid inherited Source labels from previous match launchers.

Accepted subset result

Audit controls

• Accepted publication status: corrected 48-game balanced subset.
• Raw package integrity: SHA256 verified.
• Raw package: 50 PGN games, results.json present and scheduler_state.json present.
• Raw 50-game issue: colour balance failed at 26/24 instead of 25/25.
• Accepted subset: first 48 games only.
• Accepted subset colour balance: exact 24 White and 24 Black games per engine.
• Tiebreak required: no.
• Official bracket consequence: Viridithas advances over Caissa by 26.5–21.5 on the accepted subset.

Result structure

• Accepted subset PGN result distribution: 37 wins for White, 11 draws and 0 wins for Black.
• Colour score in accepted subset: White 42.5/48, Black 5.5/48.
• Viridithas by colour: 22.5/24 as White and 4.0/24 as Black.
• Caissa by colour: 20.0/24 as White and 1.5/24 as Black.
• Termination distribution in accepted subset: 37 checkmates, 6 threefold repetitions and 5 insufficient-material results.
• Total recorded TB hits in accepted subset: 2,588,019.

Correction note

• The raw 50-game result was Viridithas 28.5–21.5 Caissa.
• The raw 50-game result is not used as the official bracket result because the final mirrored cycle was incomplete.
• The excluded games are the last two games of the raw package, both from the incomplete final C25 block with Viridithas as White.
• This restores balanced engine colours but does not claim the originally intended 25 mirrored opening units.
• Operational action: the Ubuntu Node launcher must be corrected so it advances the opening only after the complete colour-reversed mirrored unit and stops on a contract that preserves colour balance.

Audit controls

• Final state: 396/396 games closed.
• Engines: 12.
• Per-engine state: 66 games, 33 White and 33 Black for every engine.
• Scheduler state: openingIndex 396 and pending null.
• Mirrored structure: 198/198 mirrored units closed.
• Pair ratio: 0.
• PGN/JSON parity: 396/396.
• Top added-phase score: Stockfish dev-20260426-1a882efc with 52.0/66.
• Added phase Top 8 by score: Stockfish, Reckless, Obsidian, Alexandria, Viridithas, Caissa, Clover and RubiChess.

Operational caveat

• proxy_fatal terminations in added phase: 180.
• Affected engines: berserk-avx2-d432net, integral-avx2 and plentychess-avx2.
• Each affected engine completed the structural contract of 66 games, but their scores include systematic UCI/proxy failures.
• Forward action: replace the previous Berserk engine identity with Berserk 14 before future matches.
• Publication doctrine: the rating surface includes the closed results, and the operational caveat remains disclosed rather than hidden.