Full Report for AlmaTafl by Paschalis Antoniou

Full Report for AlmaTafl by Paschalis Antoniou

AlmaTafl is an abstract strategy game influenced by the Tafl family of games, where one player controls the invaders(Black) and one player controls the defenders (White and Red).

Generated at 2024-12-09, 04:38 from 1000 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!

Special Spaces

Throne
The central space is the throne, where the king starts. Only the king can occupy the throne (unless the invaders can capture the king there).
Escape space
The marked spaces at the edge of the board are escape spaces; only the king can land there, and will win by doing so.

Stacking

Miscellaneous

General comments:

Play: Combinatorial

Family: Combinatorial 2023,Tafl games

Mechanism(s): Capture,Movement,Race

Components: Board

Level: Advanced

BGG Stats

BGG EntryAlmaTafl
BGG Rating8.06154
#Voters13
SD0.733315
BGG Weight2
#Voters1
Year2023

BGG Ratings and Comments

UserRatingComment
acd767.8
malloblenne7
dreamingant8
r0cka7
mrraow8Seems like a good game. With bounce moves and stacking, it has come a long way from its Tafl roots; you need a completely different set of strategies to win.
raphaell79
schwarzspecht8
JamieRufe8Rating: Enthusiastic Impressions after first play I really enjoyed my first play! First of all, I love the asymmetry between the two players. I played as the King in this game and it was so much bouncing the King around the board. It was especially fun to win this game off of a king bounce! I think Almatafl is the type of abstract design that modern board gamers would really enjoy.
anastasiou198710
alekerickson8
thenexusgame8
hiimjosh8Super fun abstract. I already liked Tafl style games, and this amps it up quite a lot. The hex board is nice, but it's really the addition of stacking that makes this cool. The king bounce is the final cherry on it all. Fantastic.
nestorgames8Looks interesting.

Kolomogorov Complexity Analysis

Size (bytes)32051
Reference Size10915
Ratio2.94

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 second10166.73 (98.36µs/playout)
Reference Size504641.18 (1.98µs/playout)
Ratio (low is good)49.64

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

Samples1608001 
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 playout11,803931,435,1067,14912283
search.UCT10,87913,5732614
search.AlphaBeta197,75055,8754949

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.

Heuristic Values

This chart shows the heuristic values thoughout a single representative* game. The orange line shows the difference between player scores. (* Representative, in the sense that it is close to the mean game length.)

Win % By Player (Bias)

1: Invaders win %15.40±2.10Includes draws = 50%
2: Defenders win %84.60±2.37Includes draws = 50%
Draw %5.40Percentage of games where all players draw.
Decisive %94.60Percentage of games with a single winner.
Samples1000Quantity 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         
2UCT (its=3)63103399700.6200 <= 0.6505 <= 0.679962.470.0037.5399.94
44UCT (its=45)63103199500.6336 <= 0.6642 <= 0.693549.050.0050.9581.14
45
UCT (its=46)
305
0
302
607
0.4628 <= 0.5025 <= 0.5421
39.37
0.00
60.63
70.82
46
UCT (its=46)
504
0
496
1000
0.4731 <= 0.5040 <= 0.5349
38.00
0.00
62.00
69.10

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.

Complexity

Game length76.82 
Branching factor62.53 
Complexity10^126.87Based on game length and branching factor
Samples1000Quantity 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 Size73Quantity of distinct board cells
Distinct actions835Quantity of distinct moves (e.g. "e4") regardless of position in game tree
Killer moves53A 'killer' move is selected by the AI more than 50% of the time
Too many killers to list.
Good moves475A good move is selected by the AI more than the average
Bad moves360A bad move is selected by the AI less than the average
Terrible moves9A terrible move is never selected by the AI
Terrible moves: g2-j2,c5-f2,f9-f6,g9-j6,i7-f10,e10-h7,f3-f6,e10-b10,i3-f6
Response distance%27.21%Distance from move to response / maximum board distance; a low value suggests a game is tactical rather than strategic.
Samples1000Quantity of logged games played

Board Coverage

A mean of 56.05% of board locations were used per game.

Colour and size show the frequency of visits.

Game Length

Game length frequencies.

Mean76.82
Mode[500]
Median44.0

Change in Material Per Turn

Mean change in material/round-0.19Complete 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.

Trajectory

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 first player never had the advantage. The lead changed on 0% of the game turns. Ai Ai found 3 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 moves95.1399.6991.53
Mean no. of effective moves48.3577.7925.07
Effective game space10^116.4110^64.1910^52.21
Mean % of good moves63.3824.3594.23
Mean no. of good moves21.7817.1825.42
Good move game space10^74.7310^21.6310^53.10

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

MeasureValueDescription
Hot turns40.26%A hot turn is one where making a move is better than doing nothing.
Momentum14.29%% of turns where a player improved their score.
Correction57.14%% of turns where the score headed back towards equality.
Depth2.99%Difference in evaluation between a short and long search.
Drama0.00%How much the winner was behind before their final victory.
Foulup Factor96.10%Moves that looked better than the best move after a short search.
Surprising turns2.60%Turns that looked bad after a short search, but good after a long one.
Last lead change-1.30%Distance through game when the lead changed for the last time.
Decisiveness6.49%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.)

Opening Heatmap

Colour shows the success ratio of this play over the first 10moves; black < red < yellow < white.

Size shows the frequency this move is played.

Unique Positions Reachable at Depth

012345
1906570298314815963313751066

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)

            

3932 solutions found at depth 5.

Puzzles

PuzzleSolution

Defenders to win in 4 moves

Defenders to win in 5 moves

Defenders to win in 6 moves

Defenders to win in 5 moves

Defenders to win in 5 moves

Defenders to win in 4 moves

Defenders to win in 4 moves

Defenders to win in 4 moves

Defenders to win in 3 moves

Defenders to win in 3 moves

Defenders to win in 4 moves

Defenders to win in 4 moves

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