Full Report for SLLUG(7x7,0-3,1.5 Komi,Opponent) by Stephen Tavener

Full Report for SLLUG(7x7,0-3,1.5 Komi,Opponent) by Stephen Tavener

Inspired by Slitherlink, but ended up more like Libraria.

Generated at 03/10/2020, 04:44 from 124856 logged games.


Representative game (in the sense of being of mean length). Wherever you see the 'representative game' referred to in later sections, this is it!


Put a random number in each square of the grid.


Each turn, draw a line on the edge of an unclaimed square, or pass.

After placing, check any neighbouring squares to see if they are claimed; a square is claimed if it has exactly as many neighbouring lines as the number in it. The player with the most neighbouring lines claims the number. In the case of a tie, the non-moving player gets the number.


The game ends when both players pass in succession. Players add their claimed numbers, and the highest score wins. Draws are possible, but rare.


To offset the first player advantage, 1.5 komi seems to work well.


SLLUG is kinda short for SlitherLink-Like Game.


General comments:

Play: Combinatorial

BGG Stats

BGG EntrySLLUG(7x7,0-3,1.5 Komi,Opponent)
BGG Ratingnull
BGG Weightnull

Kolomogorov Complexity Analysis

Size (bytes)28900
Reference Size10293

Ai Ai calculates the size of the implementation, and compares it to the Ai Ai implementation of the simplest possible game (which just fills the board). Note that this estimate may include some graphics and heuristics code as well as the game logic. See the wikipedia entry for more details.

Playout Complexity Estimate

Playouts per second12366.06 (80.87µs/playout)
Reference Size204687.34 (4.89µs/playout)
Ratio (low is good)16.55

Tavener complexity: the heat generated by playing every possible instance of a game with a perfectly efficient programme. Since this is not possible to calculate, Ai Ai calculates the number of random playouts per second and compares it to the fastest non-trivial Ai Ai game (Connect 4). This ratio gives a practical indication of how complex the game is. Combine this with the computational state space, and you can get an idea of how strong the default (MCTS-based) AI will be.

Playout/Search Speed

LabelIts/sSDNodes/sSDGame lengthSD
Random playout2261213,691726617

Random: 10 second warmup for the hotspot compiler. 100 trials of 1000ms each.

Other: 100 playouts, means calculated over the first 5 moves only to avoid distortion due to speedup at end of game.

Mirroring Strategies

Rotation (Half turn) lost each game as expected.
Reflection (X axis) lost each game as expected.
Reflection (Y axis) lost each game as expected.
Copy last move lost each game as expected.

Mirroring strategies attempt to copy the previous move. On first move, they will attempt to play in the centre. If neither of these are possible, they will pick a random move. Each entry represents a different form of copying; direct copy, reflection in either the X or Y axis, half-turn rotation.

Win % By Player (Bias)

1: White win %48.96±0.28Includes draws = 50%
2: Black win %51.04±0.28Includes draws = 50%
Draw %0.00Percentage of games where all players draw.
Decisive %100.00Percentage of games with a single winner.
Samples124856Quantity of logged games played

Note: that win/loss statistics may vary depending on thinking time (horizon effect, etc.), bad heuristics, bugs, and other factors, so should be taken with a pinch of salt. (Given perfect play, any game of pure skill will always end in the same result.)

Note: Ai Ai differentiates between states where all players draw or win or lose; this is mostly to support cooperative games.

UCT Skill Chains

MatchAIStrong WinsDrawsStrong Losses#GamesStrong Scorep1 Win%Draw%p2 Win%Game Length
1UCT (its=2)63103599900.6069 <= 0.6374 <= 0.666748.690.0051.3160.53
5UCT (its=6)63103509810.6127 <= 0.6432 <= 0.672646.690.0053.3159.69
16UCT (its=17)63103619920.6057 <= 0.6361 <= 0.665548.080.0051.9260.04
26UCT (its=27)63103439740.6173 <= 0.6478 <= 0.677249.900.0050.1059.64
38UCT (its=39)63103069370.6427 <= 0.6734 <= 0.702748.240.0051.7659.42
51UCT (its=52)63103519820.6121 <= 0.6426 <= 0.671946.840.0053.1659.23
UCT (its=65)
0.5925 <= 0.6230 <= 0.6525
UCT (its=65)
0.4731 <= 0.5040 <= 0.5349

Search for levels ended: time limit reached.

Level of Play: Strong beats Weak 60% of the time (lower bound with 95% confidence).

Draw%, p1 win% and game length may give some indication of trends as AI strength increases.

1st Player Win Ratios by Playing Strength

This chart shows the win(green)/draw(black)/loss(red) percentages, as UCT play strength increases. Note that for most games, the top playing strength show here will be distinctly below human standard.


Game length59.44 
Branching factor52.81 
Complexity10^94.34Based on game length and branching factor
Samples124856Quantity of logged games played

Computational complexity (where present) is an estimate of the game tree reachable through actual play. For each game in turn, Ai Ai marks the positions reached in a hashtable, then counts the number of new moves added to the table. Once all moves are applied, it treats this sequence as a geometric progression and calculates the sum as n-> infinity.

Move Classification

Distinct actions113Number of distinct moves (e.g. "e4") regardless of position in game tree
Good moves17A good move is selected by the AI more than the average
Bad moves96A bad move is selected by the AI less than the average
Samples124856Quantity of logged games played

Board Coverage

A mean of 0.00% of board locations were used per game.

Colour and size show the frequency of visits.

Game Length

Game length frequencies.


Change in Material Per Turn

This chart is based on a single representative* playout, and gives a feel for the change in material over the course of a game. (* Representative in the sense that it is close to the mean length.)


Table: branching factor per turn, based on a single representative* game. (* Representative in the sense that it is close to the mean game length.)

Action Types per Turn

This chart is based on a single representative* game, and gives a feel for the types of moves available throughout that game. (* Representative in the sense that it is close to the mean game length.)

Red: removal, Black: move, Blue: Add, Grey: pass, Purple: swap sides, Brown: other.


This chart shows the best move value with respect to the active player; the orange line represents the value of doing nothing (null move).

The lead changed on 20% of the game turns. Ai Ai found 2 critical turns (turns with only one good option).

Position Heatmap

This chart shows the relative temperature of all moves each turn. Colour range: black (worst), red, orange(even), yellow, white(best).

Good/Effective moves

MeasureAll playersPlayer 1Player 2
Mean % of effective moves26.9225.0928.82
Mean no. of effective moves3.973.234.72
Effective game space10^17.2210^7.4710^9.75
Mean % of good moves33.4762.383.57
Mean no. of good moves14.2224.703.38
Good move game space10^35.3010^30.3410^4.96

These figures were calculated over a single game.

An effective move is one with score 0.1 of the best move (including the best move). -1 (loss) <= score <= 1 (win)

A good move has a score > 0. Note that when there are no good moves, an multiplier of 1 is used for the game space calculation.

Quality Measures

Hot turns81.36%A hot turn is one where making a move is better than doing nothing.
Momentum28.81%% of turns where a player improved their score.
Correction30.51%% of turns where the score headed back towards equality.
Depth3.03%Difference in evaluation between a short and long search.
Drama0.24%How much the winner was behind before their final victory.
Foulup Factor6.78%Moves that looked better than the best move after a short search.
Surprising turns0.00%Turns that looked bad after a short search, but good after a long one.
Last lead change66.10%Distance through game when the lead changed for the last time.
Decisiveness15.25%Distance from the result being known to the end of the game.

These figures were calculated over a single representative* game, and based on the measures of quality described in "Automatic Generation and Evaluation of Recombination Games" (Cameron Browne, 2007). (* Representative, in the sense that it is close to the mean game length.)

Unique Positions Reachable at Depth


Note: most games do not take board rotation and reflection into consideration.
Multi-part turns could be treated as the same or different depth depending on the implementation.
Counts to depth N include all moves reachable at lower depths.
Inaccuracies may also exist due to hash collisions, but Ai Ai uses 64-bit hashes so these will be a very small fraction of a percentage point.

Shortest Game(s)

No solutions found to depth 3.



White to win in 11 moves

White to win in 7 moves

Black to win in 7 moves

White to win in 8 moves

White to win in 9 moves

White to win in 8 moves

Black to win in 8 moves

White to win in 8 moves

Black to win in 7 moves

White to win in 7 moves

Weak puzzle selection criteria are in place; the first move may not be unique.