Full Report for Coalesce by Stephen Tavener

Full Report for Coalesce by Stephen Tavener

Coalesce is a simple unification game.

Generated at 08/02/2022, 16:27 from 2366 logged games.

Rules

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

Contract phase

Player 1 places any number of black pieces on the board.

Player 2 chooses to play Coalesce (Black) or Divide (White).

Play

Players alternate playing stones, starting with Divide.

If Coalesce connects all their stones into a single group, they win.

If this becomes impossible, Divide wins.

Miscellaneous

General comments:

Play: Combinatorial

Mechanism(s): Connection

BGG Stats

BGG EntryCoalesce
BGG Ratingnull
#Votersnull
SDnull
BGG Weightnull
#Votersnull
Yearnull

Kolomogorov Complexity Analysis

Size (bytes)29619
Reference Size10673
Ratio2.78

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 second108597.68 (9.21µs/playout)
Reference Size481301.44 (2.08µs/playout)
Ratio (low is good)4.43

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.

State Space Complexity

% new positions/bucket

State Space Complexity65993512 
State Space Complexity bounds62543412 < 65993512 < ∞ 
State Space Complexity (log 10)7.82 
State Space Complexity bounds (log 10)7.80 <= 7.82 <= ∞ 
Samples1291167 
Confidence0.000: totally unreliable, 100: perfect

State space complexity (where present) is an estimate of the number of distinct game tree reachable through actual play. Over a series of random games, Ai Ai checks each position to see if it is new, or a repeat of a previous position and keeps a total for each game. As the number of games increase, the quantity of new positions seen per game decreases. These games are then partitioned into a number of buckets, and if certain conditions are met, Ai Ai treats the number in each bucket as the start of a strictly decreasing geometric sequence and sums it to estimate the total state space. The accuracy is calculated as 1-[end bucket count]/[starting bucklet count]

Playout/Search Speed

LabelIts/sSDNodes/sSDGame lengthSD
Random playout124,8391,0826,534,07056,336528
search.UCT60,1473,177615

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: Player 1 win %44.63±1.99Includes draws = 50%
2: Player 2 win %55.37±2.01Includes draws = 50%
Draw %0.00Percentage of games where all players draw.
Decisive %100.00Percentage of games with a single winner.
Samples2366Quantity 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
0Random         
1UCT (its=2)63102739040.6673 <= 0.6980 <= 0.727034.620.0065.3851.64
14UCT (its=15)63103529830.6114 <= 0.6419 <= 0.671322.690.0077.3151.72
27UCT (its=28)63103669970.6025 <= 0.6329 <= 0.662323.470.0076.5352.43
65
UCT (its=9053)
421
0
395
816
0.4816 <= 0.5159 <= 0.5501
1.59
0.00
98.41
53.65
66
UCT (its=9053)
503
0
497
1000
0.4721 <= 0.5030 <= 0.5339
2.50
0.00
97.50
61.77

Search for levels ended. Close to theoretical value: player 2 wins.

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.

Complexity

Game length34.13 
Branching factor44.47 
Complexity10^54.57Based on game length and branching factor
Computational Complexity10^6.12Saturation reached - accuracy very high.
Samples2366Quantity 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

Board Size61Quantity of distinct board cells
Distinct actions64Quantity of distinct moves (e.g. "e4") regardless of position in game tree
Killer moves1A 'killer' move is selected by the AI more than 50% of the time
Killers: Choose White(Divide)
Good moves37A good move is selected by the AI more than the average
Bad moves27A bad move is selected by the AI less than the average
Response distance%37.03%Distance from move to response / maximum board distance; a low value suggests a game is tactical rather than strategic.
Samples2366Quantity of logged games played

Board Coverage

A mean of 52.67% of board locations were used per game.

Colour and size show the frequency of visits.

Game Length

Game length frequencies.

Mean43.30
Mode[34]
Median31.0

Change in Material Per Turn

Mean change in material/round0.91Complete round of play (all players)

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.)

Actions/turn

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.

Unique Positions Reachable at Depth

012345
1611891378815597366508883

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 5.

Puzzles

PuzzleSolution

Player 2/Divide/White to win in 7 moves

Player 2/Divide/White to win in 7 moves

Player 2/Divide/White to win in 3 moves

Player 1/Divide/White to win in 5 moves

Player 1/Coalesce/Black to win in 5 moves

Player 1/Coalesce/Black to win in 5 moves

Player 1/Coalesce/Black to win in 5 moves

Player 1/Coalesce/Black to win in 5 moves

Player 1/Coalesce/Black to win in 5 moves

Player 1/Coalesce/Black to win in 5 moves

Player 2/Divide/White to win in 5 moves

Player 2/Coalesce/Black to win in 5 moves

Selection criteria: first move must be unique, and not forced to avoid losing. Beyond that, Puzzles will be rated by the product of [total move]/[best moves] at each step, and the best puzzles selected.