Full Report for Chess by Traditional

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!

Standard chess.

Miscellaneous

General comments:

Requires αβ search to play well.

BGG Stats

BGG Entry	Chess
BGG Rating	7.20674
#Voters	36416
SD	1.84821
BGG Weight	3.6539
#Voters	2794
Year	1475

BGG Ratings and Comments

User	Rating	Comment
ACTP	N/A	Played by lo
1copse	7	While not always the best game for the given moment, it's pretty much the Best Game. Objectively.
jctaylor2	10	Come on now - I can't believe that anyone seriously thinks "Tigris & Eurphrates" or some-such is a BETTER game than chess! As the saying goes, chess is a fountain from which a flea can drink and an elephant can bathe. Pretty much says it all. And you can ALWAYS find an opponent, day or night, live or over the 'net. Play it at any level and it's a load of fun - 10 times the strategy and 10 times the tactics of whatever crap we're happening to play in our niche hobby that is modern boardgaming ....
cmartin	10
tha JJ	10
adularia25	6	I am a rather unorthodox Chess player. My strategies tend to be random at best. Usually I am looking so far ahead into other players strategies that I miss obvious moves. And while I can hold my own if I have to, it is not my favorite game to play. Granted, in eighth grade I did organize a Chess group in my math class, but that was more to get out of math than it was because I was passionate about Chess. The one person I have never played against is my husband - he was a master Chess player back in high school - playing those five-minute crazy timed Chess matches and winning every time. I respect him too much to submit him to my insane tactics. (Why is it everyone forgets that the king can attack? Sure, it probably won't win you the game, but it's not like he's a totally worthless piece!) However, that said, I do have the most beautiful fantasy Chess set. In truth, I have it more because the figures are just awesome than because I regularly play.
adamscottstewart	5.001	Xavier likes to play this.
Abraxox	6	Well ... that's a classic and still one of the best games ever if you go down into the strategies. It feels like your pure intellect is fighting it out with your opponent's. Clash of the brains! But nevertheless I don't play it that often, because it is just to exhausting and not really relaxing. It feels more like working than like playing.
Pierre_Tellis	10
gsong	10	Perfection! Obsession.
adambadura	8	2011-01-13 (rating 8): I decreased the rating as I go more and more into games with some theme (especially trains theme). 2010-04-14 (rating 9.8): I always liked Chess very much and previously used to play from time to time. Now I rarely play I am a weak player. Also since I learned Go I like Chess less. Chess seem to be simpler and shallower than Go while having more rules (mainly due to more kind of figures). But still I like this game very much.
2d20	8	Great game of course and it doesn't suffer as bad as other abstract but it does basically come down to the one who makes the most mistakes. I suppose that is the point but not that fun for me. Would rather invest the decent amount of time for these with other games. Saying that I can appreciate Chess for the iconic game that it is and fun to breakout once and a while!
drakezeus	10	Classic "Hall of Fame" game. Incredibly even matched game for two players. Over analyzed game but let see where some of the games of today are 200 years from now, then compare.
aCardboardBox	8	Classic game that should be enjoyed at similar skill levels unless objective of the game is to learn the game.
acharland	6	Learning: Teaching: Comment:
Admiral Fisher	8	You might say that this should be a 10, and I can see many, many arguments for that. The fact is though, that very few people master this to any great degree or other. Nevertheless, I enjoy it. It is very pure and I have a beautiful Greek set of bronze pieces.
Varthlokkur	10	The ultimate strategy game.
Dreamshadow	10	Well, not much to say for this game, it's wonderful to play against a good opponent.
Scooter	10
Aal101	9	complete
adesireg	10	Classic
hreimer	10	I own several chess boards/games.. the greatest war game of all time
adamolanna	7	ci giocavo da piccolo
ssmooth	10
aca83	10	Jugadores: 2 Tengo varios. Algunos, con las damas en el dorso.
brbender	10	The grandmaster of all games.
ansuredarke	10
acekim	7	10 year old rates: 8 -- "nobody ever wants to play in our house" 8 year old rates: 2 -- "because [10 year old] beats me all the time" 5 year old rates: N/A
Maritime	10	Haha! The Other Universal Game has a 7.20 rating? Whatever!
a2greg	7	Classic. Waiting for it to come to my GameBoy Advance. Still waiting...
2amp	5	2 exactly equal sides. booring. i moved on to wargames!
Torin	10
75dragon	10	yes
Grouchy	10
Acenoid	7	Another classic game.
fvincent	10	A classic that can't be beat.
Queue	10
filou	10	It's been great for centuries, what is there to say? I love the double blitz variant. In the realm of classic pure abstract games I prefer go.
93MadeGames	5	Right down the line with this classic game. I think I prefer reading about the history of the game than being beaten in less than ten moves.
Diatomite	10
Adanedhel	9	¿Qué decir del archiconocido e histórico juego quemamentes para 2 de todos los tiempos? xD El rey de los abtractos, y seco como él solo. La ventaja es que usas energía renovable si te quieres freir un huevo en la calva. No, yo de momento no tengo de eso último... Y... tampoco soy tan flexible!
mrcode925	10
manolovila	10
ACForward	10	I'm about a club player level. Play it for fun but have been slowly getting better. Happy to play with anyone!
3sapphires	7	2 p
Adures	8	Classic Rules are easy to remember, but game is really hard to master. With wooden set it's even better. Highly recommend it.
advancedLemon	7	It's chess. Of course it's genius!
Mad Jack	10	The ultimate 2 player abstract strategey game. May not appeal to dice rollers. Nothing else deserves a 10.
nadle	10
Stephan	10
Skyjack	10
theorgg	10
jancourtois	10
adastra	6	Played Chess a lot in high school. It takes too long to live up to my capability.
414448	3	All the open information paralyzes my brain. The complete lack of random elements makes this game pretty hard to enjoy unless you play against somebody equally good/bad - you just don't ever seem to enjoy a lucky win against a stronger opponent. The complete lack of theme makes it unengaging. Abstract games are not interesting to me, and this games never tells a story. These sentiments probably say more about me than they do about chess .
JRSchulke	10
AdosCze	9	Great game for it's age ! Infinite replaybility, improves logical thinking and is being played profesionally...
adam.skinner	7	I'm not a Chess fanatic. I enjoy the game, I know how the pieces move and the general tactics and strategy in the game. I do not know the names for the beginning sequences or anything like that. In fact, I really dislike that aspect of chess - that's it's so well known and has been played so much that you're just acting out a script, until someone deviates from it. You're playing out the same games other people have, over and over again. I'd rather play Go or Navia Dratp, but Chess enjoys widespread popularity and I still enjoy playing ... against people who regard it as a game!
Adwak1	6	don't play this one too much anymore. still have a board I picked up in mexico that has Aztec and Incan pieces.
3pic_Win	7	What can I say? It's Chess. Everybody knows about it, almost everybody over the age of 8 has played it, and it never gets old. (At least not figuratively)
Paul Slavich	10	One of the all-time great games. I wish I could find someone at my level. Very serious players are too good, and very casual players are not good enough.
nighthawk326	10
WritelySo	10
mosh247	10
ACandelieritroy20	7	Classic game, not much to say
Marcus de Bassus	10
rorschah	10	Chess used to be my favorite game. But I've found after years of playing and studying go, and a little bit of time spent studying chess, that my craving for chess has diminished. The depth and profundity of the early go game has this thickness and texture that chess doesn't for me... and the wildness and creativity and intensity of the shogi endgame makes me far happier than the ultra-calculative chess endgame. These days, I'd almost always rather go with go or shogi than chess... my chess sets come out way more for bughouse than the original...
Munter	10	Classic King of all Games. Not very fun or social game but still masterpiece.
adstille	6	I know the rules well but I am not strategic, slow or serious when I play.
victor-rr	10
3idolon	4	It's chess.
Acrerake	5	Modded figures... Megatron gifted. Not playable as chess any more ♟
1awesomeguy	8	Classic game! Worst part of the game is playing against people who memorize patterns. Without that, it is a great strategy game. One of the best in all of history.
Colonnello Vincent	10
Actherion	4	An enduring classic, and deservedly so (though overanalyzed), but it just doesn't grab me. It feels a bit limited and seems to reward memorization of certain gamestates to an extreme degree. It is easy to teach and makes a good "gateway" game, but for my gaming time there are fresher, more interesting, and more fun games out there (for the time investment, at least). There are almost certainly better abstracts in terms of strategic depth and balance, but cultural inertia makes it unlikely that any game to come will be played by a larger group of people. For me at least, it's better as an intellectual exercise than as a game.
TimTheEnchanter	10
Marco Lippolis	10
521tiger	10	Learned it way back in my very first part of live. Always was fascinated by the way great chess-players are doing their work...
aaronseeber	5	I admire this game, but would usually rather play something else. Over-analysed for my taste.
Addboilingwater	10	CLASSIC (2) Strategically Outmaneuver Your Opponent To Take The Kings. Other Versions To Note: Asymmetric - Peasants Revolt, Horde Chess, Monster Chess Chaos - Atomic, Stealthy Bomber Confuse - Alice In The Looking Glass, Synchrony Chess Find More Variants Online
jtisdel	10	The game.
ardanos	10
yesfantina	10	but it hurts my brain these days
Beelzebub	10	The fundamental strategy game.
kcsaff	10
stuque	10	Fascinating game, although it requires a lot of study to play well. Most fun when you play someone of the same ability as you.
willburnham	10	THE game. This was indeed my first wargame.
David M	10
A skinned math nerd	2	The game itself is great. For the version I'm rating here, the stench of this Chinese product is hardly bearable.
Forlindon	10	The best two player pure strategy game ever. The more you learn, the less you realize you know about playing.
Chuckles	10	Any game that can repay the endless study chess inspires is deservedly a 10.
abeille_joyeuse	5	I'm not saying it cannot be a good game, but I don't feel I master the game, expecially figuring out the opponent's strategy, so most of the time I feel my moves ignore whatever he is doing... I don't quite appreciate playign blindly like that.
Helmut	10
Gummi	10
Xanville	10
Buzz	10	Has stood the test of time for a reason. Downside is all the opening book knowledge required to play at the higher levels.
Jeremy	10
atlanticomm	10	Only wish I were better at it.
2018	6	I played a lot of chess one year. Somehow got to 1900 ELO on chess.com Wasn't good at it but for every move i'd sit literally for hours thinking about every decision before committing to one (i often played correspondence chess, where you had a lot of time to make a move). I absolutely love the mind-games aspect of it. But i don't like abstract games, nor heavy memorization and dry pattern recognition. On the other hand, on a casual level those aren't required. Chess has staying staying power no doubt. It is well rounded and deep. Just not what i'm looking for fun-wise.
bodlaender	10
abodi	3	not keen on learning all the plays. played this enough as a kid.
Aeldaar	10	One of my favorites.
TimT	10
UmExcuseMe	10	One set at work
ABandlaTroy20	9	Chess is a classic game that is an amazing tool for mental development. There are no rules that are flawed in this game and planning out steps in advance may help you win more.
Abreu	5	Well... its Chess.
daroro	10
Kloindel	10
AdmiralCrunch	6	Learned from my father. Loved it growing up, but haven't played in awhile. Plays are definetly off on this one, but i didn't start recording to recently. Most people know chess and already have emotions about it one way or the other. Myself; I have a nostalgic fondness for it, but I would rather play a more modern game if given the chance.
adamscott	9	Easily my most played game. Most of those plays were online blitz long before I discovered modern games. I always wanted to be good at chess, but the need to study/memorize openings always felt like work. I also often didn't enjoy games without time limits as I always preferred to move quickly rather than analyze every move to death. For these reasons, and despite playing it a ton, I never progressed beyond an intermediate level. Now that I have played so many modern games, I'm less enthusiastic about chess. A game played quickly and aggressively between two evenly matched players is still a great experience though.
Coach K	10	I love playing chess. Can´t find enough players that can play though.
woodstock20000	10
Alkorahil	10
1 Family Meeple	5	CLASSIC
AcemanBR	7	Por que colocar Xadrez nesta lista? Porque é um jogo que vale a pena ser jogado!
dddwwwhhh	10	1.) e4, best by test.
propsero	10	The most pure game out there. Perfect information for all players, endless strategies, playable at all levels of skill.
ebenbe	10
AndreasKissavos	10	Simply the game I have played the most and will never tire of playing.
Terror	10
4McTavish	4	C:B1
4characters	6	I enjoy chess quite a bit, but it is hard to play a casual game, it seems most people are not interested at all or they are some hypercompetitive chess nerd, either type of opponent takes the fun out of the game. The best thing about chess is the sense of scholarship -- it has been in play in the West for centuries and generations have devoted significant time to studying it and perfecting its play, fueling its growth into a full-blown sport where the top tier players retain celebrity status. The interesting dynamic about chess is that it builds up to a crescendo with the initial opening maneuvering giving way to a blood bath which seems to indeed evoke the feeling of a climactic battle. Unfortunately chess is a deeply unforgiving game, and all the fancy maneuvering to assure interlocking defenses and mutually supporting units falls apart with a single blunder, which is almost always the way someone loses in the game at the amateur levels, as opposed to being defeated by superior strategy.
acrah	10	Really, this is the ultimate game and the game with which I started. It may not have as much theme as other games (unless you can imagine it as a battle... which I do), but it has other advantages - most significantly, you can go anywhere in the western-world and there will be somebody to play and grow against. Seriously, I've more than once felt that all the time I've put into euro-games and the like would have been better put into this. It certainly would have been a lot cheaper.
Abner1	2	Lost any interest when announcement made that proof had been made that there is a "winning" strategy. Let computers play computers and don't tell chess fans and they would enjoy it just as much
aautio	6	The definitive two-player strategy board game. All skill and no luck. I certainly enjoy it every once in a while, but admittedly I'm not very good at it and it's not very exciting..
AdMan2015	N/A	2-2
grimawormtongue	10	Possibly the perfect game.
AbbyP	3	It's been overtaken by other games, to an absurd degree. Some classic abstract strategies, like Go, hold up, but this one just doesn't.
fledermaus	10
Coffeemanuksr	10
covertc	10	The best strategy game ever invented. Period.
adonismayhem	4	I play games for enjoyment. This game seems more about ego (or the players that I have played with anyway)
Gregarius	10	I am by no means a great player, but I will never tire of playing this game.
Aahz	7	I own Lego Vikings chess set, vinyl mat chess board with large pieces, and other chess sets.
2ndinBeautyContest	10	This game is simply the best. Its scandalous underranking on BGG is a comment on the inadequacy of those who have ranked it. They are simply not worthy.
Fellgray	10	God, can you get any better than this game?
A Haar	7	A classic, first game I ever learned to play as a kid. Plenty of other games I would rather play but I always have a good time with Chess.
adelfaidah	8	a really good abstract game that I play every now and then, but too much of a lifestyle type of game for me for something that never receives new content
maryesme	10	This is my all-time favorite abstract strategy game. Mostly because I can always find and opponent. Many others that I like(Go, Shogi, Octi) always require going out of my way to teach a less than willing victim.
zydoz	10	The classic abstract game in western civilization. You can spend your life on it and never got tired.
300 Lutefisks	N/A	The oldest chess set I got was from my aunt Sherye when I was in elementary school.
7hsgameclub	N/A	Notes from the perspective of a Middle School Game Club: Always popular, a classic.
nafod81	10
acaldeira99	N/A	2 Players
Geppeddooo	10	How could I not rate Chess the 10 or 10s. I got into all other games through chess. I played a lot of USCF tournaments in the past, got to "A" player level, have been away from the scene, and an getting back into it.
31rhcp	10	The definitive strategy game. You can learn to play in an hour, get pretty good in a few weeks, but mastering the game takes a lifetime.
pansophism	10	Every gamer alive should own this one. No luck in chess, only error. Playing vs. a computer does not get the same rating though.
8thDay	6	...everybody owns a chess set. Ubiquitous.
Adomasas	6	The only game people will build their personality around.
JayHuber	10
MikeOberly	10	The most exciting board game ever invented. Comments like 'the game will be solved by computers in x years' are really silly, since the game is really a battle of the minds; it's a fight between two players, not a bunch of scripted moves. The aspect of the game which really sets it apart for me is that the great games played throughout history are immortal works of art to those who understand the game. I've probably played many thousands of games, and whenever I play an equal or better opponent I never fail to get surprised, even when I seem to have everything well in hand. A beautiful and mysterious game.
onestream	10
Helloween	10	The quintessential abstract strategy board game to which others stand in awe. The tactical combinations therein are more intricate than in any other game. Also, players have complete freedom over "style", e.i. one may play very stubborn, patient and defensive(Steinitz, Petrosian, Kramnik), or one may be a ruthless "romantic" attacker(Morphy, Marshall, Fischer).
aaarg_ink	3	120910 Just can't handle the thinkiness of the game. I would play it if it was the only choice available, but I'd rather play checkers or Xiangqi instead.
Aardvark Sam	7	Chess is a classic, but you have to religiously study it to be great at it. I prefer games where someone with zero (or relatively little) experience can jump in, figure out the dynamics, and outstrategize their opponents. With chess, you have to memorize all kinds of openings, strategies, and such to be really great. I prefer Chess 960 (the Bobby Fischer variant) to straight-up Chess.
Stavros	10	The absolute classic game in Western civilization. You can enjoy it even if your level of play is not very good; the only drawback is that the gap in skill between the players is not too high, if not it kills the interest for both players. It can be played in various formats : rapid chess (blitz), casual play and problems solving. One particular and unusual use of the chessboard is the retro-analysis problems : you only need to know the rules in order to try to solve puzzles. A real blast if you like logical puzzles! I strongly recommend the book "The Chess Mysteries of Sherlock Holmes" by Raymond Smullyan)
1000rpm	9	Zero luck, massive number of games possible, deep strategy, evil moves, easy to find someone to play, low set up time, variants (suicide, speed, clock).....
hanuman	10
Xabbu	10	This is one of the greates games ever invented!
elevenbutnine	10	Always loved chess and always will.
Tyler	10	Simply Classic.
artsoma	10	Don't say that this is not a war game. I think bad things when I play chess.
latindog	10	Classic -- perhaps my favorite game.
-Johnny-	5	(gift/free/prize)
adrim	8	My rating: 8 Ratings based on my daughter's enjoyment with this game. Rating 6 -> @ 5 years old Rating 7 -> @ 6 years old Rating 6 -> @ 7 years old
Aalnakishly21Troy	8	Chess is a really chill game where you can learn really quickly. It makes you think about every move you make and sometimes you have to think 3 moves ahead.
AdamMcD	6	I won't play against slow (even kind of slow) players. Win or lose, slow games aren't fun. I realize chess is sophisticated, etc., and I get why others like it. I, however, just can't get into it.
adamphipps11	8	2 Players Best: 2
iBrow	10
Aecios	8	El primer juego al que jugué
aadrian13	10	Played over 1000 games. That deserves a 10.
Aarontu	9.8	Good, straight, solid, strategy. Especially fun with a chess clock. I don't play it often though, because it just isn't fun if both players aren't at relatively the same skill level. I'll play this when I'm in the mood for an intellectual exercise; but when I want relaxed fun, I'll play something else. That said, the game is very much a classic that is very traditional and a part of our culture, and I think it is a very good game to know how to play well. With a chess clock and a short time limit for each player (i.e. Speed Chess), the game is INTENSE and way fun!
1mileis2	N/A	At Mouse Silicon International Chess. Pretty much exactly the set I was looking for.
Abstractite	10	A game appreciated in western culture. Aesthetically pleasing. The pieces have a lot of character. They're fun to handle, and the thinking is complex. It's even relaxing just to see how the pieces move about on the board. It's beautiful even when your opponent demolishes you.
adalbert	9.5	Excellent abstract game but prone to AP:) That's why I prefer to play rapid/blitz variations.
abdekker	9	With by far the largest number of players (in the West), the most number of dedicated web sites and books and a massive, and growing, international presence this game deserves its status as the premier boardgame. Everybody should at least know how to play this game.
Aristophanes	10
A Friend of Grouchy	10	The problem with a rating system that takes account of every one of thousands (?) of ratings is that everything ends up between 5.2 and 7.6. Really, Chess:6.963 out of 10. By pure coincidence that's were Earth was rated by 1,000,000 alien nations. I can understand if you say you'd prefer to play Advanced Squad Leader or Awful Green Things From Outer Space but show you have a sense of perspective people! Chess is a truly awesome battle of intellects, think Fisher vs Spaskey - when did another board game ever capture the imagination of the planet in such a way? If you rate chess at 6.9 or less you mustn't be any good at it!
Brian McGovney	10
abyss-keeper	10	you just love this game and the 2 team variation
AdmiralACF	4	I don't think Chess is a bad game, I just have no desire to play it. I need some semblance of theme in my games. Games between amateurs are uninteresting to me, and I don't want to invest the time to learn the game's intricacies. It's just not for me.
tomgale	10
BabyRaisinGator	10	Classic. I've spent way too much time playing and purchasing books, many of which I haven't had a chance to read. Truly an addiction.
adomescik	8.5	(+) Pieces with different movements, almost everyone knows how to play, good mixture of tactics and strategy, has a lot of depth to the gameplay (-) No theme, no variable setup, prone to AP
wiiki	10	What can you say? The standard by which all others are measured.
adealisadeal	7	This game is really good. It is the best idea of simple but complex. The one thing is if there was a point system or another way to end the game. I find it sometimes annoying that when you have SUCH AN ADVANTAGE, you can loose on the clock. That is the one flaw though, and its not the end of the world.
zeriphon	10
95after5	10	MY FIRST WAR GAME EVER (EVEN WHEN CONSIDERING COMPUTER GAMES)
a1bert	6	I have two sets.
1point21gigawatts	8.5	I've played nearly 300 online games, but rarely ever play it with a physical board face-to-face. It's a wonderfully balanced 2 players game.
5pointer	7	Own two copies: 1. Disney figures. 2. Hand-carved wooden Yugoslavian set from my late Grandma
Abdul	4	Rewards memorisation and AP. I don't have the patience to play this properly.
8janek8	N/A	szachy turniejowe no.4 2 klasa Szafraniec
adebisi	5	2009-09-12 Can you see the great theme, where two mighty kingdoms battle fiercely against each other in esperate battle? 2015-04-23 4->5 Staying true to my other ratings, I cannot honestly have Chess rated as a "four". It is a solid abstract even at today's standards. There is nothing broken about it. The game has a rather steep learning curve for an abstract. First, all pieces follow unique rules of movement. Once you have the basics mastered, you have to memorise several openings to avoid check-mate in first few rounds. Next you have to train yourself to concentrate so that you can easily plan several moves ahead. To master Chess you have to play a lot which is something very few are willing to do. I certainly understand why many people do not enjoy playing Chess. It takes so much computing power to go through all possible permutations and in the end you still end up doing something silly and get kicked into face for it. But at least compared to Go, Chess is easier to analyse. Usually, key plays change the balance on the board immediately so that it is easier to see what went wrong and learn from your mistakes. And the fact that Chess does not shine in casual / occasional playing will keep people away.
booje	10
Adaphon	10	Perfect strategy game; I've played since I was a five year. 10/10, absolutely love it, am a rated player, no notes. I don't log plays as I have played literally thousands of games of chess, online and OTB, rated and unrated.
ABCafe	N/A	B5
Adeptus	8	I really like to play Chess, a simple to learn, hard to master game of abstract strategy and opponent-anticipation. I'm not what you can call a very good player, but i'm just "not that bad". ^_^
redikilowatt@msn.com	10

Kolomogorov Complexity Analysis

Size (bytes)	89362
Reference Size	10915
Ratio	8.19

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	433.97 (2304.28µs/playout)
Reference Size	1780943.90 (0.56µs/playout)
Ratio (low is good)	4103.79

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 Complexity	6495358322
State Space Complexity bounds	55479228 < 6495358322 < ∞
State Space Complexity (log 10)	9.81
State Space Complexity bounds (log 10)	7.74 <= 9.81 <= ∞
Samples	147826
Confidence	0.00	0: 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

Label	Its/s	SD	Nodes/s	SD	Game length	SD
Random playout	448	10	132,419	2,396	295	86
search.UCT	445	29			131	82
search.AlphaBeta	103,285	13,527			151	45

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: White win %	54.22±3.02	Includes draws = 50%
2: Black win %	45.78±2.99	Includes draws = 50%
Draw %	18.58	Percentage of games where all players draw.
Decisive %	81.42	Percentage of games with a single winner.
Samples	1055	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.

UCT Skill Chains

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
5	UCT (its=6)	283	665	52	1000	0.5850 <= 0.6155 <= 0.6452	17.70	66.50	15.80	259.72
6	UCT (its=6)	257	514	229	1000	0.4830 <= 0.5140 <= 0.5449	23.50	51.40	25.10	233.03

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 length	128.92
Branching factor	25.45
Complexity	10^164.75	Based on game length and branching factor
Samples	1055	Quantity 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 Size	64	Quantity of distinct board cells
Distinct actions	7534	Quantity of distinct moves (e.g. "e4") regardless of position in game tree
Killer moves	516	A 'killer' move is selected by the AI more than 50% of the time Too many killers to list.
Good moves	4503	A good move is selected by the AI more than the average
Bad moves	3027	A bad move is selected by the AI less than the average
Terrible moves	746	A terrible move is never selected by the AI Too many terrible moves to list.
Response distance%	39.31%	Distance from move to response / maximum board distance; a low value suggests a game is tactical rather than strategic.
Samples	1055	Quantity of logged games played

Board Coverage

A mean of 90.14% of board locations were used per game.

Colour and size show the frequency of visits.

Game Length

Game length frequencies.

Mean	128.92
Mode	[117]
Median	128.0

Change in Material Per Turn

Mean change in material/round	-0.20	Complete 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 19% of the game turns. Ai Ai found 6 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

Measure	All players	Player 1	Player 2
Mean % of effective moves	77.16	67.91	86.56
Mean no. of effective moves	18.18	20.15	16.17
Effective game space	10^146.56	10^77.94	10^68.63
Mean % of good moves	45.94	68.97	22.56
Mean no. of good moves	13.10	20.83	5.25
Good move game space	10^101.73	10^79.47	10^22.26

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

Measure	Value	Description
Hot turns	66.67%	A hot turn is one where making a move is better than doing nothing.
Momentum	31.78%	% of turns where a player improved their score.
Correction	34.88%	% of turns where the score headed back towards equality.
Depth	7.05%	Difference in evaluation between a short and long search.
Drama	0.59%	How much the winner was behind before their final victory.
Foulup Factor	87.60%	Moves that looked better than the best move after a short search.
Surprising turns	21.71%	Turns that looked bad after a short search, but good after a long one.
Last lead change	27.13%	Distance through game when the lead changed for the last time.
Decisiveness	4.65%	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.)

Openings

Moves	Animation
P e2-e4,P e7-e5,N g1-f3,N g8-f6,N f3xe5,Q d8-e7,P f2-f4,N f6xe4,B f1-e2,Q e7-c5,P d2-d4
P e2-e4,P e7-e5,N g1-f3,N g8-f6,N f3xe5,Q d8-e7,P f2-f4,N f6xe4,B f1-e2,Q e7-c5
P e2-e4,P e7-e5,N g1-f3,N g8-f6,N f3xe5,Q d8-e7,P f2-f4,N f6xe4,B f1-e2
P e2-e4,P e7-e5,N g1-f3,N g8-f6,N f3xe5,Q d8-e7,P f2-f4,N f6xe4
P e2-e4,P e7-e5,N g1-f3,N g8-f6,N f3xe5,Q d8-e7,P f2-f4
P e2-e4,P e7-e5,N g1-f3,N g8-f6,N f3xe5,Q d8-e7
P e2-e4,P e7-e5,N g1-f3,N g8-f6,N f3xe5
P e2-e4,P e7-e5,N g1-f3,N g8-f6
P c2-c4,P g7-g6,P e2-e4,P f7-f6
P g2-g3,N b8-a6,P d2-d4,N g8-f6
P a2-a3,P d7-d5,P f2-f4
P a2-a3,P g7-g6,P h2-h4

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

0	1	2	3	4	5
1	20	420	9322	136507	2182089

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)

4 solutions found at depth 4.

Puzzles

Puzzle	Solution
Black to win in 5 moves
Black to win in 5 moves
White to win in 5 moves
Black to win in 5 moves
Black to win in 3 moves
Black to win in 3 moves
White to win in 3 moves
White to win in 3 moves
Black to win in 3 moves
White to win in 3 moves
White to win in 3 moves
Black to win in 3 moves

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