Full Report for Connect 4 by Howard Wexler,Ned Strongin

Full Report for Connect 4 by Howard Wexler,Ned Strongin

Make a row of 4, with gravity.



Each turn, place a piece in an empty square so that it is supported below.


Make a line of 4 to win.


General comments:

Play: Combinatorial

Family: Line games

Mechanism(s): Pattern

Components: Board

Level: Beginner,Standard

BGG Stats

BGG EntryConnect 4
BGG Rating4.8575
BGG Weight1.2055

BGG Ratings and Comments

atkinsstN/AGifted to Mark
Auzette2Dis. Connect. 4. Ever.
alkaiser6[Children's Game] My kids can play this over and over. They love it. The game drives me insane though. It's pretty much one step above tic-tac-toe for me. But they love it so I'll play it with them.
Arctic Jack6A better game than it is probably given credit for by most. A great platform for budding young abstractees too. I bought this book to deeper understand Connect 4. The Complete Book of CONNECT 4: History, Strategy, Puzzles by James D. Allen A good abstract, well worth it's cheap price. I wish a larger grid was also commercially available.
Ammarg4variation of tic tac toe
alanykl3How to play? Just the same as the name: Connect Four.
Apathy6This game is basically tic tac toe, but it'll always be fun for me. I'm not sold on the new ways to play the new version of Connect 4. The pop out game is not fun at all, and I mainly just prefer the classic game.
Arcturian5A childhood classic that's still fun to play on occasion.
adularia252Of all the variants of tic-tac-toe, this one seems like it should be so much more... and yet it disappoints like the rest. Either you crush your opponent because they don't see what you are doing, or you lose because you lost track of how many they had in a row. Either way, I despise playing this and would rather play tic-tac-toe (at least it ends faster.)
Altugas5A nice classic, with more strategy than it may seem.
Cheryllion9Here, diagonally! Pretty sneaky, Sis!
alexanderbanning5ABSTRACT, CHILDREN'S Travel edition. A thrift store find. Recommended with 2 players. 10 mins.
Admiral Fisher4A good one for kids and adults can play it and get a modicum of enjoyment from it. We have a wooden set called "4 in a row"
asta3AT MUM AND DAD'S I have a travel version. Fun for children.
AwesomeMike4it's a solved game but i'd still give it a go again
AnyMouseN/AI adore connect four. I don't care that it's "solvable" as I don't play with anyone who's studied the dissertation.
adamolanna5Vaghi ricordi di alcune partite giocate prima del 1985, mi piaceva molto, lo trovavo strategico e difficile.
aca8310Jugadores: 2 Tengo varios
ArtB3down from 4 likely won't play this again although could be convinced played many times before I began recording plays
Abso2Suffers from the same fate as Tic-tac-toe. Fun at start but eventually turns out into a draw or a loss by just counting the remaining turns and who happens to drop the final piece.
acekim5Not too bad for playing with small children just learning logic and how to block ones opponent. Much superior to Candyland...
a2greg6Classic. Nuff said.
IWilloughbyTroy179you have to get four pieces in a row going diagonal, vertical, or horizontal. There are games that have no winners too.
Anakin19812A simple game for kids.
atlcribber5For those not ready for pente, there is connect four.
airship51N/ACaptain's Mistress - wood w/glass marbles.
Ajax6Classic game. Adds a little more strategy to tic-tac-toe. My daughter enjoys it, and I don't hate it.
balderin8.5This is an excellent game to play with my five year old. He wins about fifty percent now. Lots of fun. We can knock out about ten games in fifteen minutes.
alethic4One of those kids games that kids don't actually seem to enjoy a lot, but game theorists do.
Artax5Gyerekorunk ismert jateka.
Asociacion_El_DuendeN/AAño 1996
AnttiT3.3As a child, I played this quite a lot. It can be entertaining, but will become repetitive if you play too long.
Olley Mauley Mim10Great game to play with KIDS. I have to rate it higher based on that fact. ANYONE can play. And if any KID proposed a game of Connect Four, I'd play it. :-)
Asmoridin3.5Again, probably loved this as a kid. Growing to being an adult, it's just too simple for me to want to play again. Played it again as an adult... still pretty simple, but can be fun on occasion =).
AndyHowell7There's a pretty fun bar in Arlington that has a giant Connect 4 set. I had so much fun playing it (with a bunch of other type-A overly competitive military officers) that I've got to raise my rating. I'm always up for a game of Connect 4. Also, my two year-old is starting to play a little.
amishburrito5A great game from my youth. I used to play this every day in elementary school with friends while the rest of the class had recess outside. Very simplistic for an advanced gamer though.
arhtu7McDonald's edition. ;)
Baggioo6For children
alextrovN/ATravel version
bacusgod3A game with actually some strategy that just can't be compared to more recent, great games.
amwiles1Not a game. All plays are recorded from Yucata.de.
astroglide5i shouldn't care about games being solved unless i can actually do it myself. a master would no doubt blow me away at this game. fairly fun, easy to teach abstract with quick playing time. i'm sure i'll play it with my kids when i have some.
adstille6Great game that I kept for decades but it eventually became boring.
The Bus9
binraix9Classic game. I played this one in kindergarten and still love it. Very simple and still hard one if you have a good opponent! Recommend to math geeks out there!
Arnott5Basic, but still fun.
alexmate6Fairly fun game.
ajewoN/AClassic, abstract game that works especially well with kids. Similar games: * Qwirkle
AnnC5.504+ or 06+, 2 player, 10 mins.
AeneasN/APre.owned italian version "Forza 4"
alcatraz135Fast and superlight!
aaronseeber4I had a lot of fun with this one as a kid, which gains it a point. Might not quite be my thing these days.
123SimPYN/Arode kruis editie
Alberto_Mena4It was a "must have" when it came out, more than 40 years ago.
Ashavan3Intro: Kua Klassen
areeves5Always a fun game to play with kids and adults.
agieseN/AStorage - Box 12
pingouin519One of my favourite games with Deluxe MAster Mind. No luck involved!
anazagarus4A simple game, that if both players play optimally will be decided by who plays first. Playing with mixed-age pairings is tough, because the superior player will win always and easily.
amatyarakshasa8A fantastic game to play with children!
Alannamairead3I wouldn't care if I never ever played this again in all my life
adamscott5Meh. Thrift Store find. Donated to my classroom, where it has been played hundreds (no exaggeration) of times.
1 Family Meeple5It's a classic.
LoganDGarcia10So I'm biased because it's the game my fiancee and I played a lot when we were in college. But its a great game. Play several times win or lose always fun.
Aussie5506I play this with my 3 yr old...which usually involves putting tokens in as quickly as possible one after the other and shouting "I win!" when you mak a row of four...sooner or later I'm sure he'll get the idea and then it's hex and counter brainwashing time! Still playing. Now the boy is five we have progressed to the proper rules.
ArmbarN/AWhy am I so bad at this?
alfonzosN/ASomething to play with kids who are too sophisticated for Tic Tac Toe but not ready for Go Moku.
arbitrarychoice4Classic children's pure strategy game. Not much to it after you figure out the main strategies.
AuntbeastN/A$1.98 Bought it because it was the German version. YAY! I have a German game! (never played, game still with packing intact
Htrinh00008.253/1/17: In storage
amodman2One of the few universal abstracts that's actually more or less "solved." I mean, it was a fun idea when I was a kid and it is a neat use of components. But yeah, not really much of a real game.
Apparos Achaparos3For kids mostly. Grownups should find it very shallow and lacking.
antoinedebruxelles6Puissance 4 Fond memories, like to trash my kids from time to time :)
cass_xoxo1610This is a good game beacuse it's easy and fun!
Cmot Dribbler8.5Great game!
2ndinBeautyContest5Quick with some strategy. Satisfying way to get the pieces out at the end of the game.
Anthares6A very good classic. Great for kids and adult too.
gecykkah9I love playing this one with kids. You can often get a good laugh out of them by making really bone-head obvious fours-in-a-row vertically or across the bottom horizontally. Kids are usually up for playing silly variants, like dropping two at a time instead of one.
alfredo lorente5.5A classic abstract that seems simpler than it is. After all, gravity is a harsh mistress, and you need to play with her as much as you play against your opponent. It may not be a "Gamer's classic," but there are many more much worse choices in the toy departments of the Walmart's of the world.
max_ra10This game is mostly undervalued. It is really strategical. You have to force your opponent to take the row you wnat him to take. You have to creat double-traps to win the game.
Area512Busy 4 is my favorite Band.
baboon6With a brutal opponent, this can be a real game. Playing with kids can be tiresome. Also, I seem to recall the older versions being built a lot better.
Professor Brick8.1
autumnweave77 is my rating for playing with non-gaming adults. 9 is my rating for playing with kids. I love playing this with my nine year old niece, and we do not tire of it. When we are together we play this day after day. We play best out of five and it's tricky enough that she will sometimes win, especially if I lose my concentration, and that keeps both of us on our toes. For playing with adults who have a lot of gaming experience I would chose something else.
Don E9
ArchiN/A1985 FX Schmidt
aaarg_ink9151105 Good memories for days gone by. Such a perfect tactile experience. 111130 something hypnotic about...I could play again and again. I'm certain its been solved, but is it easily solved? I'm not sure...I guess I should look it up sometime. Later.
happy_272810A classic game for kids.
1000rpm7Great fun in the pub or garden (with a giant set). Also great for kids - taking turns, strategy, visualisation, etc.
AndersonCouncil4It's a simple game and fun but not one I'd take along to a game night with me. It's good for playing with small children though as it's so easy to learn.
pathagobi9Okay this is one of THE classics!!! I just love this game... all you have to do is get 4 in a row (any direction) and you say "connect 4!!!" This game for me is a timeless classic that is so much fun!!!
Anemelos2A simple abstract game. Its a game for kids.
Alex the Pretty Good5A good combo of strategy and deduction. Starts to get predictable after a few games with the same opponent though.
Aarontu5A simple, if slightly juvenile, abstract game.
mafiul10Best 2 player game (No luck, only brain)
alemfi1Unlike tic-tac-toe, the decision space is a bit too big to quickly teach them that a game can be "solved".
Andy Mesa6It's glorified tic-tac-toe but I still enjoy it.
awleong5OK game to have lying around as it is quick and it is easy to get someone to play. I have a wooden version called "Captain's Mistress".
Algernon885Quite good a game, after all. Just not something you would ask to play, more like you won't refuse to play it if someone else wants to.
Iron Knight10
Asociacion NoctisN/A?
schaferlove8This one never gets old. A true classic.
Ace Pumpkin5Game Folio/Fun-on-the-Run/travel edition
adebisi3You're just repeating the same patterns over and over and wishing that your opponent will not see them
Bagherra1I don't particularly care to play solved games. It is a nice game for learning how to write computer games though.
The Eraser10
arnest_r5Feels solved (yes, I know it IS solved), playing it feels almost like Tic Tac Toe
airjudden4This is really a kid's game, but it's one of the more enjoyable ones that I play with them. It has enough "oomph" that a couple of adults could squeeze in a quick game without being bored, and it's fast enough that it won't bore you for a long time (unlike Monopoly).
Appetyte5Classic I used to play when I was a child.
BrandenTheFirst10Connect Four has been a staple board game for me since my youth and I can say it's easily one of the first games I'd truly enjoyed when it comes to true strategy. Realistically, It's about a step above tic-tac-toe but it's also just different enough to keep that simple formula entertaining and fresh. I'd recommend this game to anyone just getting into board games as it's a good way to start expanding your thought process for more complex games. That being said- Connect Four has an optimal strategy but is one of the best in terms of beginning board games and will always hold a special place in my heart due to experiences with my family and friends.
Master Mind9
ayedub4Another kid's game...I use to love it, but really it's a bit simplistic by today's standards.
AndrePOR6Classic (Before 2000)

Levels of Play

AIStrong WinsDrawsStrong Losses#GamesStrong Win%p1 Win%Game Length
Grand Unified UCT(U1-T,rSel=s, secs=0.01)360036100.0058.3312.19
Grand Unified UCT(U1-T,rSel=s, secs=0.20)35294678.2647.8335.24

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)13131
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 second1308215.59 (0.76µs/playout)
Reference Size660763.84 (1.51µs/playout)
Ratio (low is good)0.51

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 %51.11±1.63Includes draws = 50%
2: Black win %48.89±1.63Includes draws = 50%
Draw %7.02Percentage of games where all players draw.
Decisive %92.98Percentage of games with a single winner.
Samples3618Quantity 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

LabelIts/sSDNodes/sSDGame lengthSD
Random playout2,652,77068,98456,536,8841,469,167217

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 length36.18 
Branching factor5.73 
Complexity10^26.03Based on game length and branching factor
Samples3618Quantity of logged games played

Move Classification

Distinct actions42Number of distinct moves (e.g. "e4") regardless of position in game tree
Killer moves2A 'killer' move is selected by the AI more than 50% of the time
Killers: d2,d4
Good moves27A good move is selected by the AI more than the average
Bad moves15A bad move is selected by the AI less than the average
Samples3618Quantity 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 first player held the advantage throughout the game. The lead changed on 0% of the game turns. Ai Ai found 1 critical turn (turns with only one good option).

Overall, this playout was 34.29% 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


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)





Black to win in 21 moves

White to win in 15 moves

White to win in 21 moves

Black to win in 9 moves

White to win in 17 moves

White to win in 17 moves

White to win in 17 moves

Black to win in 13 moves

Black to win in 9 moves

Black to win in 7 moves

White to win in 13 moves

Black to win in 5 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.