Part 1: Welcome, Format & Rules
Football has its Nations League. Now chess engines have theirs.
Sixteen of the strongest engines written by European authors. Sixteen national flags. Four groups, one trophy. The seeding, the groups, the home-and-away rhythm and the knockout bracket all mirror the real 2026/27 UEFA Nations League A, as closely as chess allows.
THE MIRROR IN SHORTHow does an engine get its flag?
Strictly by strength. The engine ranked N on my rating list takes the nation ranked N in the official UEFA League A seeding. Number 1, Reckless, wears the shirt of Portugal, the reigning champions. Number 2, PlentyChess, plays for Spain - the team Portugal beat on penalties in the 2025 final.
- 16 nations in 4 groups of 4, taken directly from the real UEFA draw
- Every pairing meets twice: at home (White) and away (Black), with the same opening
- Every game is a match: 3 points for a win, 1 for a draw
- Top 2 of each group go to the quarterfinals
- Two-legged quarterfinals, then semifinals and the final
- Extra time and penalties when a knockout tie is level
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Feature | Tournament Details |
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Tournament Name | UNL 2026 - 100% UEFA Nations League Mirror |
Tournament Type | Double Round-Robin (Group Stage) + Knockout |
Hardware | Intel Core i5-8500 3.00GHz, 16GB RAM |
Operating System | Windows 11 Pro x64 |
GUI | Arena Chess GUI |
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Time Control | 3m + 2s (Standard Blitz) |
Hash | 256 MB |
Tablebases | 5-men Syzygy |
Engine Threads | 1 (Single Thread) |
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GROUP STAGE | |
Matches per group | 12 (Double Round-Robin, 4 engines) |
Games per match | 1 (home = White, away = Black) |
Openings | Same opening for both legs of a pairing |
Total games per group | 12 |
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KNOCKOUT STAGE | |
Quarterfinals | 4 games (two legs of 2 games, aggregate) |
Semifinals | 6 games (3m + 2s) |
Final | 8 games (3m + 2s) |
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EXTRA TIME (if drawn) | 10 games (9s + 0.1s) |
PENALTIES (if drawn) | W/B pairs (2s + 0.1s) until one pair is decisive |
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Opening Book | 4 Super-GM openings (6 moves, anti-draw) |
Engine Version Lock | 10/10/2026 00:00 GMT |
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- Every game is a match: win = 3 points, draw = 1 point, loss = 0
- A win is a goal: every decisive game ends 1-0
- The home engine plays White, the away engine plays Black
- Both legs of a pairing use the same opening
- The top 2 of each group advance to the quarterfinals
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1. Points
2. Head-to-head points
3. Head-to-head goal difference
4. Head-to-head goals scored
5. Goal difference (all group matches)
6. Goals scored (all group matches)
7. Elo rating (no drawing of lots - engines have objective ratings!)
If criteria 2-4 separate only some of three or more tied engines,
they are reapplied to the engines still tied.
- Each tie is a mini-match: quarterfinals 4 games, semifinals 6, final 8
- Every decisive game win counts as one goal; drawn games are ignored
- Quarterfinals: two legs of 2 games, goals on aggregate; the group winner hosts the second leg
- Level after normal time: extra time (10 games, 9s + 0.1s)
- Still level: penalties (W/B pairs, 2s + 0.1s) until one pair is decisive
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Group | Nation | Engine | Elo |
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A1 | France | Alexandria 9.1.0 | 2982 |
A1 | Italy | Caissa 2.0.0 | 2976 |
A1 | Belgium | Hobbes 3.0.0 | 2958 |
A1 | Turkiye | Astra 7.0.0 | 2946 |
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A2 | Germany | Obsidian 16.0 | 2980 |
A2 | Netherlands | Viridithas 20.0.0 | 2974 |
A2 | Serbia | Clover 9.1 | 2960 |
A2 | Greece | Starzix 6.0 | 2936 |
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A3 | Spain | PlentyChess 8.0.0 | 2990 |
A3 | Croatia | Integral 8.0 | 2970 |
A3 | England | Stormphrax 8.0.0 | 2956 |
A3 | Czechia | Motor 0.9.0 | 2940 |
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A4 | Portugal | Reckless 0.9.0 | 2995 |
A4 | Denmark | Pawnocchio 2.0.1 | 2972 |
A4 | Norway | RubiChess 20240817 | 2950 |
A4 | Wales | Renegade 1.3.1 | 2930 |
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- Draw restriction: no two engines whose authors share a country in the same group
- National touch: Astra (TUR) swapped with Renegade within pot 4, so that it plays for its author's own country, Turkiye
- The four groups are separated by less than 4 Elo on average - a very balanced draw
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Tie | Home in leg 1 | Home in leg 2 | Games |
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QF1 | Runner-up A2 | Winner A1 | 4 |
QF2 | Runner-up A1 | Winner A2 | 4 |
QF3 | Runner-up A4 | Winner A3 | 4 |
QF4 | Runner-up A3 | Winner A4 | 4 |
SF1 | Winner QF1 | Winner QF3 | 6 |
SF2 | Winner QF2 | Winner QF4 | 6 |
Final | Winner SF1 | Winner SF2 | 8 |
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Engines from the same group cannot meet before the final.
The group stage will be reported in three parts, one round (two matchdays, home and away) per post, just like the international windows in football. Then the knockout stage.
Part 2: Matchdays 1 & 2 - coming next.
English translation and BBCode formatting assisted by Claude (Anthropic AI - claude.ai)