Full Report for Yodd by Luis Bolaños Mures

Full Report for Yodd by Luis Bolaños Mures

Yodd is an elegant connection and territory game for two players.

Generated at 6/14/23, 3:20 AM 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!

Definitions

A group is a set of connected, like-colored stones. A single stone is also a group.

Rules

Starting with Black, players take turns placing one or two stones of any color on empty points. On his first turn, Black can only place one stone.

At the end of each turn, there must be an odd number of groups on the board (i.e. the sum of the number of Black and White groups must be an odd number).

Players can pass their turn at any moment, unless it violates the previous rule (this means Black can't pass on his first turn).

When both players pass in succession, the game ends. The player with the fewest groups on the board wins.

Miscellaneous

General comments:

Play: Combinatorial

Family: Combinatorial 2012

Mechanism(s): Territory

Components: Board

BGG Stats

BGG EntryYodd
BGG Rating7.5
#Voters17
SD1.33945
BGG Weight2
#Voters2
Year2011

BGG Ratings and Comments

UserRatingComment
luigi879My game.
ZickzackN/AElegant and innovative rules, would like to know more about gameplay
rayzg7.5It feels like a connection game where you get to place your opponent's goals! Ensuring that there's always an odd number of groups would be really, really, really annoying to play unless you're playing with a computer UI. It lost some ratings points because of that.
mrraow6Interesting constraint, but not very exciting to play.
FinlistN/AMYO PenP
CoreyClark10MY goodness this game is deep. This is possibly a bigger happy accident than Go.
milomilo122N/AI've now played Yodd twice, and it's square-board analogue, Xodd, once. I much prefer Yodd. Impressions so far: First, the game's concept is more than a little intriguing. It's so coherent and simple and sensible that you can't believe no one's thought of it before, which to me is the hallmark of a beautiful idea - the inventor deserves high recognition for this. Staying connected across the center is important, since it allows you to keep your groups better connected. On the other hand, there's also incentive to build structures one or two rows away from the edges, because you can build "cages" for opponent stones there most easily. If it turns out that there's good balance between these two themes, Yodd could be a great game. As it is, my early impressions are positive. I discovered some interesting, unusual tactics immediately and some strategy considerations revealed themselves readily. There was no "I'm totally lost" feeling from which so many abstracts suffer. All to the good. If there's anything that annoyed me, it's that you need to keep track of how many groups, or even better, how many virtual groups both you and your opponent have, and it's hard to do, and I found myself recounting frequently. Maybe some kind of score track could remove this issue. On the other hand, only the difference in group number need be tracked really, so maybe this would become effortless with additional play.
King Lear10Yodd is amazing beautiful game. I am always up to a good game of Yodd at igGamesCenter!
orangeblood7Another enjoyable design from Luis Bola�os Mures. My appreciation for Yodd really shot up after playing against strong competition on a size 8 hex. There is very interesting board-wide strategy on larger boards.
Talisinbear7
simpledeep9
schwarzspecht7
hojohN/AF
m-s-voss8Playing on self made board using "Go" pieces. A good abstract game. Similar to "Xodd".
grasa_total5The consequences of the "odd number of groups" rule seem to run deeper than I was able to see in one play. My total flop of an opening game (on IGGC) was described by one onlooker as "oh I've seen this strategy before" even though, like, actually I just had no idea what I was doing.
russ8This and the square-board version Xodd are both cool clever games. A practical problem occurs if there are many groups in play: sometimes we don't notice that the number of groups has accidentally/illegally become even. For that reason I recommend saying "3 4" or whatever after each turn, to consciously confirm the current number of groups each side has.
hiimjosh6I like this slightly more than Xodd because hexes, however the bigger boards take longer which is not a great tradeoff. See comments for Xodd as they are nearly identical to Yodd. Similarities to Catchup and Hex. It's okay Label: Good But Not Great
scih6.5
RichardIngram7
pezpimp7.5Based on one play: Similar mechanics to a linking game where you have to connect both sides, however in this one you must have the least amount of groups of pieces, thus you want to link them all together. You can pass at anytime and you can play your opponents pieces which is really infuriating but a great mechanic. There must also always be an odd amount of sets on the board, combined for both players, taking that into account you can't simply connect or add pieces since it would break that rule. Quite enjoyed it.
The Player of Games7

Kolomogorov Complexity Analysis

Size (bytes)29788
Reference Size10673
Ratio2.79

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 second2225.35 (449.37µs/playout)
Reference Size556235.40 (1.80µs/playout)
Ratio (low is good)249.95

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

Samples124186 
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 playout2,22112383,4922,0281732
search.UCT2,248301722

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: Black win %47.20±3.08Includes draws = 50%
2: White win %52.80±3.10Includes 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
0Random         
1UCT (its=2)63103129430.6385 <= 0.6691 <= 0.698448.670.0051.33172.60
5UCT (its=6)631036910000.6006 <= 0.6310 <= 0.660450.300.0049.70172.59
13
UCT (its=14)
597
0
403
1000
0.5663 <= 0.5970 <= 0.6270
51.10
0.00
48.90
172.52
14
UCT (its=14)
473
0
527
1000
0.4422 <= 0.4730 <= 0.5040
54.90
0.00
45.10
172.48

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 length179.74 
Branching factor128.85 
Complexity10^346.70Based 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 Size169Quantity of distinct board cells
Distinct actions339Quantity of distinct moves (e.g. "e4") regardless of position in game tree
Good moves55A good move is selected by the AI more than the average
Bad moves284A bad move is selected by the AI less than the average
Response distance%48.40%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 102.23% of board locations were used per game.

Colour and size show the frequency of visits.

Game Length

Game length frequencies.

Mean179.74
Mode[179]
Median180.0

Change in Material Per Turn

Mean change in material/round1.84Complete 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 lead changed on 10% 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 moves61.0660.0562.08
Mean no. of effective moves82.5780.9184.22
Effective game space10^210.9010^104.0810^106.82
Mean % of good moves46.0365.9026.16
Mean no. of good moves70.8077.1264.48
Good move game space10^175.1710^116.7010^58.46

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 turns47.78%A hot turn is one where making a move is better than doing nothing.
Momentum27.78%% of turns where a player improved their score.
Correction37.78%% of turns where the score headed back towards equality.
Depth15.36%Difference in evaluation between a short and long search.
Drama2.04%How much the winner was behind before their final victory.
Foulup Factor46.11%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 change49.44%Distance through game when the lead changed for the last time.
Decisiveness6.11%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

012
133857122

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 2.