Predicting Board Game Collections

VWValker’s Collection

Author

Phil Henrickson

Published

10/31/24

About

This report details the results of training and evaluating a classification model for predicting games for a user’s boardgame collection.

Note

To view games predicted by the model, go to Section 5.

Collection

The data in this project comes from BoardGameGeek.com. The data used is at the game level, where an individual observation contains features about a game, such as its publisher, categories, and playing time, among many others.

I train a classification model at the user level to learn the relationship between game features and games that a user owns - what predicts a user’s collection?

username status games
VWValker ever_owned 183
VWValker own 183
VWValker rated 104

I evaluate the model’s performance on a training set of historical games via resampling, then validate the model’s performance on a set aside set of newer relases. I then refit the model on the training and validation in order and predict upcoming releases in order to find new games that the user is most likely to add to their collection.

username years type Own
no yes
VWValker -3500-2020 train 24420 98
VWValker 2021-2022 valid 9824 73
VWValker 2023-2028 test 9087 12

Types of Games

What types of game does the user own? The following plot displays the most frequent publishers, mechanics, designers, artists, etc that appear in a user’s collection.

Show the code
collection |>
        filter(own == 1) |>
        collection_by_category(
                games = games_raw
        ) |>
        plot_collection_by_category()+
        ylab("feature")

The following plot shows the years in which games in the user’s collection were published. This can usually indicate when someone first entered the hobby.

Games in Collection

What games does the user currently have in their collection? The following table can be used to examine games the user owns, along with some helpful information for selecting the right game for a game night!

Use the filters above the table to sort/filter based on information about the game, such as year published, recommended player counts, or playing time.

Show the code
collection |>
        filter(own == 1) |>
        prep_collection_datatable(
                games = games_raw
        ) |>
        filter(!is.na(image)) |>
        collection_datatable()

Modeling

I’ll now the examine predictive models trained on the user’s collection.

For an individual user, I train a predictive model on their collection in order to predict whether a user owns a game. The outcome, in this case, is binary: does the user have a game listed in their collection or not? This is the setting for training a classification model, where the model aims to learn the probability that a user will add a game to their collection based on its observable features.

How does a model learn what a user is likely to own? The training process is a matter of examining historical games and finding patterns that exist between game features (designers, mechanics, playing time, etc) and games in the user’s collection.

I make use of many potential features for games, the vast majority of which are dummies indicating the presence or absence of the presence or absence of things such as a publisher/artist/designer. The “standard” BGG features for every game contain information that is typically listed on the box its playing time, player counts, or its recommended minimum age.

Note

I train models to predict whether a user owns a game based only on information that could be observed about the game at its release: playing time, player count, mechanics, categories, genres, and selected designers, artists, and publishers. I do not make use of BGG community information, such as its average rating, weight, or number of user ratings. This is to ensure the model can predict newly released games without relying on information from the BGG community.

What Predicts A Collection?

A predictive model gives us more than just predictions. We can also ask, what did the model learn from the data? What predicts the outcome? In the case of predicting a boardgame collection, what did the model find to be predictive of games a user has in their collection?

To answer this, I examine the coefficients from a model logistic regression with ridge regularization (which I will refer to as a penalized logistic regression).

Positive values indicate that a feature increases a user’s probability of owning/rating a game, while negative values indicate a feature decreases the probability. To be precise, the coefficients indicate the effect of a particular feature on the log-odds of a user owning a game.

The following visualization shows the path of each feature as it enters the model, with highly influential features tending to enter the model early with large positive or negative effects. The dotted line indicates the level of regularization that was selected during tuning.

Show the code
model_glmnet |> 
        pluck("wflow", 1) |>
        trace_plot.glmnet(max.overlaps = 30)+
        facet_wrap(~params$username)

Partial Effects

What are the effects of individual features?

Use the buttons below to examine the effects different types of predictors had in predicting the user’s collection.

Assessment

How well did the model do in predicting the user’s collection?

This section contains a variety of visualizations and metrics for assessing the performance of the model(s). If you’re not particularly interested in predictive modeling, skip down further to the predictions from the model.

The following displays the model’s performance in resampling on a training set, a validation set, and a holdout set of upcoming games.

Show the code
metrics |>
        mutate_if(is.numeric, round, 3) |>
        pivot_wider(
                names_from = c(".metric"),
                values_from = c(".estimate")) |>
        gt::gt() |>
        gt::sub_missing() |>
        gt_options()
username wflow_id type .estimator mn_log_loss roc_auc pr_auc
VWValker glmnet resamples binary 0.022 0.869 0.048
VWValker glmnet test binary 0.017 0.829 0.019
VWValker glmnet valid binary 0.036 0.885 0.100

An easy way to visually examine the performance of classification model is to view a separation plot.

I plot the predicted probabilities from the model for every game (during resampling) from lowest to highest. I then overlay a blue line for any game that the user does own. A good classifier is one that is able to separate the blue (games owned by the user) from the white (games not owned by the user), with most of the blue occurring at the highest probabilities (left side of the chart).

Show the code
preds |>
        filter(type %in% c('resamples', 'valid')) |>
        plot_separation(outcome = params$outcome)

I can more formally assess how well each model did in resampling by looking at the area under the ROC curve (roc_auc). A perfect model would receive a score of 1, while a model that cannot predict the outcome will default to a score of 0.5. The extent to which something is a good score depends on the setting, but generally anything in the .8 to .9 range is very good while the .7 to .8 range is perfectly acceptable.

Show the code
preds |>
        nest(data = -c(username, wflow_id, type)) |>
        mutate(roc_curve = map(data, safely( ~ .x |> safe_roc_curve(truth = params$outcome)))) |>
        mutate(result = map(roc_curve, ~ .x |> pluck("result"))) |>
        select(username, wflow_id, type, result) |>
        unnest(result) |>
        plot_roc_curve()

Top Games in Training

What were the model’s top games in the training set?

Show the code
preds |>
        filter(type == 'resamples') |>
        prep_predictions_datatable(
                games = games, 
                outcome = params$outcome
        ) |>
        predictions_datatable(outcome = params$outcome,
                remove_description = T, 
                remove_image = T, 
                pagelength = 15)

Top Games in Validation

What were the model’s top games in the validation set?

Show the code
preds |>
        filter(type %in% c("valid")) |>
        prep_predictions_datatable(
                games = games,
                outcome = params$outcome
        ) |>
        predictions_datatable(
                outcome = params$outcome,
                remove_description = T, 
                remove_image = T, 
                pagelength = 15)

Top Games by Year

Displaying the model’s top games for individual years in recent years.

Show the code
preds |>
        filter(type %in% c('resamples', 'valid')) |>
        top_n_preds(
                games = games,
                outcome = params$outcome,
                top_n = 15,
                n_years = 15
        ) |>
        gt_top_n(collection = collection |> prep_collection())
Rank 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022
1 Le Havre Axis & Allies: Pacific 1940 Prêt-à-Porter Mage Knight Board Game Terra Mystica Tash-Kalar: Arena of Legends Orléans Codenames Star Wars: Rebellion Charterstone Nemesis Tainted Grail: The Fall of Avalon Hansa Teutonica: Big Box Bloodborne: The Board Game Gateway Island
2 Byzanz Shipyard Warhammer: The Island of Blood Mansions of Madness Descent: Journeys in the Dark (Second Edition) Sushi Go! Imperial Settlers Signorie Codenames: Deep Undercover Pandemic Legacy: Season 2 Rising Sun Siege of the Citadel Gùgōng: Deluxe Big Box Kingdom Come Endless Winter: Paleoamericans
3 Axis & Allies Anniversary Edition Dungeon Lords Sneaks & Snitches Pictomania Axis & Allies: 1941 Madeira Star Wars: Imperial Assault M.U.L.E. The Board Game Perdition's Mouth: Abyssal Rift Gloomhaven Everdell Zombicide: Invader Eclipse: Second Dawn for the Galaxy Ankh: Gods of Egypt Marvel Zombies: Heroes' Resistance
4 Space Alert Space Pirates Firenze The New Era Star Wars: The Card Game Hanamikoji Nations: The Dice Game Blood Rage SeaFall Anachrony The Quacks of Quedlinburg Clank! Legacy: Acquisitions Incorporated CloudAge Tabannusi: Builders of Ur Frostpunk: The Board Game
5 Senji Skyline 3000 Troyes Ora et Labora Rex: Final Days of an Empire Glass Road Three Kingdoms Redux Through the Ages: A New Story of Civilization Terraforming Mars This War of Mine: The Board Game Mage Knight: Ultimate Edition PARKS Rush M.D. Llamaland Nemesis: Lockdown
6 Android War of the Ring Battles of Westeros Gears of War: The Board Game Cockroach Poker Royal Lewis & Clark: The Expedition Praetor Heroes Scythe Gaia Project Architects of the West Kingdom Crystal Palace The Quacks of Quedlinburg: Big Box Key Pai Sho Mosaic: A Story of Civilization
7 Sorry! Sliders Axis & Allies: 1942 Flicochet Ascending Empires Warhammer 40,000 (Sixth Edition) 1775: Rebellion Arcadia Quest Mombasa Great Western Trail Massive Darkness Underwater Cities Aftermath Gloomhaven: Jaws of the Lion Rome: Rising Empires Tindaya
8 Giants Steam Warhammer: The Game of Fantasy Battles (8th Edition) Rune Age 卑怯なコウモリ (Cowardly Bat) Terror in Meeple City Fields of Arle Viticulture Essential Edition Codenames: Pictures Twilight Imperium: Fourth Edition Crown of Emara Tiny Towns Pandemic Legacy: Season 0 Boonlake Carnegie
9 Cosmic Encounter Middle-Earth Quest Space Hulk: Death Angel – The Card Game Tournay Robinson Crusoe: Adventures on the Cursed Island Francis Drake Castles of Mad King Ludwig Risk: Europe Santorini Dungeon of Mandom VIII The Estates Detective: City of Angels On Mars Marvel United: X-Men Frosthaven
10 Red November The Adventurers: The Temple of Chac Vinhos A Fake Artist Goes to New York Suburbia The Builders: Middle Ages Tiny Epic Kingdoms Oh My Goods! Imhotep My Little Scythe Gizmos HATE Tawantinsuyu: The Inca Empire Steamwatchers Skymines
11 Mutant Chronicles Collectible Miniatures Game Age of Conan: The Strategy Board Game 51st State Dungeon Raiders Keyflower Theseus: The Dark Orbit luz Steampunk Rally Arkham Horror: The Card Game Calimala Hokkaido The Hunters A.D. 2114 Lost Ruins of Arnak The Great Wall Quacks & Co.: Quedlinburg Dash
12 Kakerlakensuppe Vasco da Gama Runewars Eminent Domain Tzolk'in: The Mayan Calendar Concept Dungeon Lords: Happy Anniversary Cacao Aeon's End Mythic Battles: Pantheon Newton Judge Dredd: Helter Skelter Starcadia Quest Ark Nova Wayfarers of the South Tigris
13 Battlestar Galactica: The Board Game Cyclades Glen More The Lord of the Rings: The Card Game OddVille Canterbury Sons of Anarchy: Men of Mayhem Dungeon Saga: Dwarf King's Quest Fields of Green Flick 'em Up!: Dead of Winter Blackout: Hong Kong Zona: The Secret of Chernobyl Altar Quest Clash of Cultures: Monumental Edition Hunch!
14 Cannonball Colony Warhammer: Invasion Norenberc War of the Ring: Second Edition Ginkgopolis Deadzone Camel Up Forbidden Stars Star Trek: Frontiers Unfair Container: 10th Anniversary Jumbo Edition! Hellboy: The Board Game – Deluxe Edition Glasgow Batman: The Animated Series Adventures – Shadow of the Bat Warhammer: The Horus Heresy – Age of Darkness
15 World of Warcraft: The Adventure Game Tarantel Tango GOSU A Game of Thrones: The Board Game (Second Edition) Galaxy Trucker: Anniversary Edition Romolo o Remo? Johari Minerva Clank!: A Deck-Building Adventure Smile The World of SMOG: Rise of Moloch Star Wars: Outer Rim Florenza: X Anniversary Edition Corrosion Agricola 15

Predictions

New and Upcoming Games

What were the model’s top predictions for new and upcoming board game releases?

Show the code
new_preds |>
        filter(type == 'upcoming') |>
        # imposing a minimum threshold to filter out games with no info
        filter(usersrated >= 1) |>
        # removing this goddamn boxing game that has every mechanic listed
        filter(game_id != 420629) |>
        prep_predictions_datatable(
                games = games_new,
                outcome = params$outcome
        ) |>
        predictions_datatable(outcome = params$outcome)

Older Games

What were the model’s top predictions for older games?