Full Report for Circle of Life by Nick Bentley

Full Report for Circle of Life by Nick Bentley

Eat adjacent creatures of smaller size. Capture 20 stones to win, or stalemate your opponent.


Place a piece in any empty piece, then eat everything that can be eaten


General comments:

Play: Combinatorial,Themed

Mechanism(s): Pattern,Capture,Stalemate,Territory

Components: Board

BGG Stats

BGG Entry Circle of Life
BGG Rating 7.13036
#Voters 56
SD 1.52033
BGG Weight 2
#Voters 3
Year 2015

BGG Ratings and Comments

User Rating Comment
Starkriller 6
ChrisSmith4773 8
pwoloszun 7 Initial rating after just 2 plays. Clever abstract which is really thematic
mrraow 9 The most original game I have played in the past year; though I'm not sure I'd like to play without computer moderation, because the chance of making an error is quite high. I like the emergent feeling of predation and struggle for territory.
Gurth 4.5
1974vertigo2009 N/A PnP - 983
nunovix 4
fogus 6.1 Preliminary rating: An odd abstract strategy game that is very opaque despite the inclusion of a wheel of death.
switza 6
Rakasis 7.6 ~
mirror33 6
megamau 7
thierryhavard 8
maruXV 7
Marc_D 6
ryansdavis 6
yaron 7
aclif 8 Unique abstract strategy. Easy to learn. Hard to master
vttdavid9 7
Tolkana 5
Hensanson 8
TeChNoWC 5.7
RustedTree N/A For future reference: streamlined abstract with polyhexes and innate powers. Super interesting, want to print it and play.
js3b 8
grolapinos 9
orangeblood 6 I love most of Nick's games, but this one doesn't quite click for me. I view Bug as a similar but much superior “grow and eat” game, perhaps because the eating chain in CoL does not fire the same creative feelings in me. I also don’t like needing to look back at the chart to see who eats whom, even though I know it would come more naturally to me with more plays.
schwarzspecht 8
enavico 5 + Quite interesting abstract - First player advantage?
hojoh N/A https://docs.google.com/document/d/1B8TIPKEC5dqOFLinVsqDfKxA6Nr0u4ialSUCBtlZhPA/edit?usp=sharing
Sqrt2 N/A Custom crafted.
kefer9 7
Wentu 8.7 This game is amazing! I haven't played dozens of games but the few experiences I am having are unbelievably tense and full of surprises! the best abstract I have seen in a long time (let's say since Santorini). When there will be a good physical implementation I could raise this yet again. ------------------------------ [EDIT] This game is a blast! it has a clear plausible reference to a theme I adore, it requires tactics (a lot!!) and some strategy, a lor of pattern recognition and a good dose of evil. Extremely entertaining. -------------------------------- [EDIT] never played it, but the idea is great and I like it a lot. I wonder: does the order of feeding must really be fixed or could it be conceivable to have it changing for each game?
hawk-x- 8 Wow. This abstract is pretty boss. It's engrossing, wildly different, and has a theme that actually works as a theme?
aswegler0606 7.9 smartly crafted 2 player abstract. got a chance to playtest this and was very impressed with the balance and foresight put into the design. can't wait to play again!
ankeszu 9.1
liefde_is 8 like to play it at BGA
eusebio_babilon 7.6
djgold 10
dispatch134711 8.6 I will never not try a Nick B. game given half a chance. While necessarily not as elegant / minimalist as Catchup, given the rules of predation, Carnivores has a simple yet visceral mechanism that really gives you the feeling of evolving and then viciously consuming various beasts in constantly shifting rock-paper-scissor type matchups. Am still struggling to beat the AiAi bot, every time I think I'm winning I realise I am overcommitting to large shapes/ structures. Rule query - it seems if a piece makes a capture and a suicide, capture prevails and the creature does not commit suicide. Maybe you could message me to confirm, Nick. FWIW, here's my mnemonic for remembering who eats who - 2 piece eats singleton crooked 3 eats 2 straight 2 beats crooked 'clump' beats straight axe breaks clump snake outmaneuvers axe horse eats snake bug annoys horse boomerang takes out bug (?) ninja star is cooler than boomerang staff (4 straight) is strongest, meaning by necessity, singleton beats staff, making it a dubious play at best.
Sintonic 4 + clever game - but I don't like at all - constantly looking what figure eats what played only at BGA
timawetzel 5
EnriqueXanchez 7
grasa_total 5 One play, still learning the dynamics. Secretly a game of territory capture, not piece capture, with logic puzzles around defense. Would like it more if the 'circle of life' was small or orderly enough to learn by heart quickly, but that may be an unavoidable downside of the design. [Played in homemade version from web rulebook, no version number.]
arimarima 8 After a few plays, seems very solid. The 'circle of life' is a very interesting idea, if a little difficult to get my head around. It's a lot harder than standard paper, scissors, rock. Enough here though to keep me interested while i work out some kind of strategy.
lulu35 N/A BGA
biofarmspineto 10
girlfridaygirl N/A TWO PLAYER
MilkyJoe241 5
rseater 4 Turn based rock-paper-scissors. This game hurts my head -- it is very tactical and thinking ahead careful is extremely important. Not very heuristic. The pattern of captures among size-4 patterns seems a bit arbitrary, but there may be a deeper justification. If it really is arbitrary, I wonder what would happen if that part became a modular setup element. There seems to be a big first player, advantage, but I'm not sure. Pie rule may be needed. Overall, the game is quite clever but not my cup of tea.
EllieK 6 Tip-top abstract. Engaging and most importantly, fun. All the fun of Tash-Kalar extracted into a simple, back and forth, give and take game.
melendor 7.5
flahr 9
Tr0llet 7
tkvaran 8
PabloNevoeiro 8
Astramance 7
BankofDracula 9
zevtrantor 8
bluebee2 N/A PnP
slimy_asparagus 9 Print and play - amazingly deep but fairly quick game.
CyBear 9 DIY?
mirth00 6
Nievares 8
heggahegga N/A 2 Player

Levels of Play

AI Strong Wins Draws Strong Losses #Games Strong Win% p1 Win% Game Length
Grand Unified UCT(U1-T,rSel=s, secs=0.01) 36 0 0 36 100.00 52.78 56.25
Grand Unified UCT(U1-T,rSel=s, secs=0.07) 36 0 10 46 78.26 50.00 67.33
Grand Unified UCT(U1-T,rSel=s, secs=0.55) 36 0 9 45 80.00 44.44 68.22

Level of Play: Strong beats Weak 60% of the time (lower bound with 90% confidence).

Draw%, p1 win% and game length may give some indication of trends as AI strength increases; but be aware that the AI can introduce bias due to horizon effects, poor heuristics, etc.

Kolomogorov Complexity Estimate

Size (bytes) 29406
Reference Size 10293
Ratio 2.86

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 second 10327.75 (96.83µs/playout)
Reference Size 400914.08 (2.49µs/playout)
Ratio (low is good) 38.82

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.

Win % By Player (Bias)

1: White win % 48.50±3.09 Includes draws = 50%
2: Black win % 51.50±3.10 Includes draws = 50%
Draw % 0.00 Percentage of games where all players draw.
Decisive % 100.00 Percentage of games with a single winner.
Samples 1000 Quantity 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.

Playout/Search Speed

Label Its/s SD Nodes/s SD Game length SD
Random playout 10,256 95 635,160 5,831 62 7
search.UCB 10,383 249 63 8
search.UCT 10,464 246 66 8

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.


Game length 66.60  
Branching factor 31.70  
Complexity 10^93.18 Based on game length and branching factor
Samples 1000 Quantity of logged games played

Move Classification

Distinct actions 62 Number of distinct moves (e.g. "e4") regardless of position in game tree
Good moves 30 A good move is selected by the AI more than the average
Bad moves 31 A bad move is selected by the AI less than the average
Samples 1000 Quantity of logged games played

Change in Material Per Turn

This chart is based on a single playout, and gives a feel for the change in material over the course of a game.


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 9% of the game turns. Ai Ai found 4 critical turns (turns with only one good option).

Overall, this playout was 91.94% hot.

Position Heatmap

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


Table: branching factor per turn.

Action Types per Turn

This chart is based on a single playout, and gives a feel for the types of moves available over the course of a game.

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

Unique Positions Reachable at Depth

0 1 2 3 4
1 61 3721 111691 3242977

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 4.


Moves Animation


Puzzle Solution

White to win in 24 moves

Black to win in 20 moves

Black to win in 23 moves

Black to win in 9 moves

Black to win in 5 moves

Black to win in 15 moves

Black to win in 9 moves

White to win in 13 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.