Full Report for Bide by Alek Erickson

Full Report for Bide by Alek Erickson

Bide is a combinatorial, abstract strategy game for 2-6 players played on a hexagonal or square board which is initially empty (hex-hex base 5 is recommended). Bide was designed by Alek Erickson in May 2020.

Generated at 21/02/2021, 10:05 from 1000 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!

Players can skip turns to get extra turns later:
Players take turns placing stones of their colour in the hexagonal cells. At the beginning of your turn, you are given a new stone. You can either play it, or "bide" (meaning wait). If you bide, set the stone aside and your turn ends immediately. The stone remains in your hand. If you play the new stone while having at least one stone still in hand, you may "release" (meaning play every stone in your hand in succession). If a player releases, all opponents must immediately release next turn, including their stone for that turn.

Stones create shock waves:
When a stone is placed, it creates a "shock wave": all adjacent stones move one space in the direction radially outward from the placement. If there are multiple connected stones adjacent to the placed stone, positioned directly in the line of the shock wave, they all move one space. If this movement causes a stone to bump into another stone directly in the line of the shock wave, that stone also gets pushed one space (becoming adjacent along a different grid line does not count). However, stones cannot be pushed past the edges of the board, and lines that are full between the edges and placed stone do not move.

Players get points for owning the centre:
When the board is full, players score the position. Each stone is worth points equal to its distance from the nearest edge (starting at zero). Groups consist of connected, adjacent stones of a single colour. Groups are worth the sum of their stones. The player with the highest scoring group wins. If tied, remove the outer-most ring of pieces and re-score, repeating this process until there is a winner.


General comments:

Play: Combinatorial

Family: Combinatorial 2020

Mechanism(s): Connection,Movement,Scoring

Components: Board

BGG Stats

BGG EntryBide
BGG Rating8.31818
BGG Weight0

BGG Ratings and Comments

alekerickson10I only design games that I will always enjoy playing, so it only makes sense for me to give this a ten.
Matt19908Many of the abstracts I've played feel like merely variations on Chess, but the shockwave mechanics give Bide a character all of its own. Definitely going to play it again.
coldsalmon8The basic goal of the game is very intuitive, and the basic mechanics are fun. Create a plan, and watch it get blown to bits, then take your revenge on your opponent.
AdamCarney8.5A quick and dynamic abstract game with a high player count, Bide is one that I would almost always enjoy playing.
Zapawa9The enjoyable chaos introduced by biding and shockwaves makes the game a true delight. I don't remember myself ever having that much fun playing an abstract. At the same time, Bide seems to have varied strategies and rich tactics, it can certainly be a brain burner if you actually bother to analyze it. Playing for the sheer fun of scattering enemy pieces through the board with massive explosions is still very much valid, though.

Kolomogorov Complexity Analysis

Size (bytes)26889
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 second28431.06 (35.17µs/playout)
Reference Size2036659.88 (0.49µs/playout)
Ratio (low is good)71.64

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.

Playout/Search Speed

LabelIts/sSDNodes/sSDGame lengthSD
Random playout29,2461831,904,02911,893652

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 %52.80±3.10Includes draws = 50%
2: Black win %47.20±3.08Includes draws = 50%
Draw %0.00Percentage of games where all players draw.
Decisive %100.00Percentage 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
2UCT (its=3)63102328630.7006 <= 0.7312 <= 0.759752.260.0047.7465.07
8UCT (its=9)63103389690.6206 <= 0.6512 <= 0.680551.600.0048.4065.17
18UCT (its=19)63103239540.6308 <= 0.6614 <= 0.690852.200.0047.8064.98
33UCT (its=34)63103679980.6019 <= 0.6323 <= 0.661650.700.0049.3064.66
49UCT (its=50)63103619920.6057 <= 0.6361 <= 0.665552.120.0047.8864.52
62UCT (its=169)63101227530.8100 <= 0.8380 <= 0.862654.980.0045.0264.57
63UCT (its=458)63101848150.7443 <= 0.7742 <= 0.801652.640.0047.3665.13
64UCT (its=1245)63102178480.7137 <= 0.7441 <= 0.772354.130.0045.8765.38
UCT (its=1245)
0.5030 <= 0.5340 <= 0.5647

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 length72.41 
Branching factor31.02 
Complexity10^98.83Based 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

Distinct actions63Number of distinct moves (e.g. "e4") regardless of position in game tree
Good moves15A good move is selected by the AI more than the average
Bad moves48A bad move is selected by the AI less than the average
Response distance2.10Mean distance between move and response; a low value relative to the board size may mean a game is tactical rather than strategic.
Samples1000Quantity of logged games played

Board Coverage

A mean of 40.89% of board locations were used per game.

Colour and size show the frequency of visits.

Game Length

Game length frequencies.

Mode[72, 73]

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 4% 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 moves30.8639.6720.44
Mean no. of effective moves6.817.795.64
Effective game space10^45.4310^26.7210^18.70
Mean % of good moves24.3834.8412.01
Mean no. of good moves8.6514.671.55
Good move game space10^37.3810^32.1810^5.20

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 turns81.94%A hot turn is one where making a move is better than doing nothing.
Momentum16.67%% of turns where a player improved their score.
Correction41.67%% of turns where the score headed back towards equality.
Depth3.93%Difference in evaluation between a short and long search.
Drama3.33%How much the winner was behind before their final victory.
Foulup Factor38.89%Moves that looked better than the best move after a short search.
Surprising turns2.78%Turns that looked bad after a short search, but good after a long one.
Last lead change73.61%Distance through game when the lead changed for the last time.
Decisiveness18.06%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


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 1.



Black to win in 15 moves

White to win in 11 moves

White to win in 15 moves

White to win in 14 moves

Black to win in 9 moves

Black to win in 13 moves

Black to win in 14 moves

White to win in 6 moves

White to win in 6 moves

Black to win in 13 moves

White to win in 11 moves

Black to win in 12 moves

White to win in 11 moves

White to win in 5 moves

White to win in 5 moves

Black to win in 4 moves

White to win in 3 moves

Black to win in 12 moves

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