Predicting Board Game Collections

J_3MBG’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
J_3MBG ever_owned 574
J_3MBG own 372
J_3MBG rated 606

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
J_3MBG -3500-2020 train 24240 278
J_3MBG 2021-2022 valid 9844 53
J_3MBG 2023-2028 test 9058 41

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
J_3MBG glmnet resamples binary 0.045 0.916 0.200
J_3MBG glmnet test binary 0.027 0.886 0.051
J_3MBG glmnet valid binary 0.028 0.909 0.128

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 Battlestar Galactica: The Board Game Dominion: Intrigue DungeonQuest (Third Edition) Village Terra Mystica Lewis & Clark: The Expedition Imperial Settlers The Gallerist Star Wars: Rebellion This War of Mine: The Board Game Cosmic Encounter: 42nd Anniversary Edition Paladins of the West Kingdom Dwellings of Eldervale The Great Wall Nemesis: Lockdown
2 A Game of Thrones: The Card Game Cyclades Troyes A Game of Thrones: The Board Game (Second Edition) Wiz-War (Eighth Edition) Eldritch Horror AquaSphere 7 Wonders Duel Terraforming Mars My Little Scythe Underwater Cities Chocolate Factory Etherfields Terraforming Mars: Ares Expedition Wayfarers of the South Tigris
3 Pandemic Chaos in the Old World Dominant Species The New Era The Manhattan Project Relic King of New York Viticulture Essential Edition Scythe Anachrony Newton Tainted Grail: The Fall of Avalon Century: Golem Edition – An Endless World Ark Nova ISS Vanguard
4 Roll Through the Ages: The Bronze Age Small World Runewars Rune Age Robinson Crusoe: Adventures on the Cursed Island Forbidden Desert Pandemic: Contagion Pandemic Legacy: Season 1 Islebound Pandemic Legacy: Season 2 Nemesis Star Wars: Outer Rim Dune: Imperium Rome: Rising Empires Carnegie
5 Space Alert Shipyard Labyrinth: The War on Terror, 2001 – ? Mage Knight Board Game Keyflower Rococo Praetor Tiny Epic Galaxies Lorenzo il Magnifico Azul Everdell Clank! Legacy: Acquisitions Incorporated Viscounts of the West Kingdom Canvas Frostpunk: The Board Game
6 Dominion Imperial 2030 51st State The Lord of the Rings: The Card Game Empires of the Void Legacy: The Testament of Duke de Crecy Arcadia Quest Mission: Red Planet (Second Edition) The Manhattan Project: Energy Empire Century: Spice Road Arkham Horror (Third Edition) Tapestry The Search for Planet X Sleeping Gods Starship Captains
7 Call of Cthulhu: The Card Game Greed Incorporated 7 Wonders Puerto Rico Android: Infiltration Eight-Minute Empire: Legends La Granja Rattle, Battle, Grab the Loot Days of Ire: Budapest 1956 Twilight Imperium: Fourth Edition Brass: Birmingham Wingspan Guild Master Cascadia Woodcraft: Roll and Write
8 The Rich and the Good Thunderstone Forbidden Island Elder Sign Suburbia City of Iron Pandemic: The Cure Thunderbirds Star Trek: The Dice Game Gaia Project Architects of the West Kingdom Aftermath Pandemic Legacy: Season 0 Galactic Era The Age of Atlantis
9 Android Axis & Allies: 1942 Alien Frontiers Space Empires 4X Android: Netrunner City of Remnants Artifacts, Inc. Above and Below Kanagawa Century: Golem Edition Rising Sun Pax Pamir: Second Edition Hallertau Unsettled Bardsung
10 Stone Age War of the Ring Dominion: Big Box War of the Ring: Second Edition Archipelago Glass Road Sons of Anarchy: Men of Mayhem Risk: Europe Dead of Winter: The Long Night Gloomhaven Azul: Stained Glass of Sintra Era: Medieval Age On Mars Arkham Horror: The Card Game (Revised Edition) Shogun No Katana Deluxe Edition
11 Cosmic Encounter Finca Sid Meier's Civilization: The Board Game Belfort Zombicide Russian Railroads Fields of Arle Super Motherload Arkham Horror: The Card Game Fallout Everdell: Collector's Edition Fantastic Factories Santorini: New York Roll Camera!: The Filmmaking Board Game Endless Winter: Paleoamericans
12 Cavum Ad Astra Dungeons & Dragons: Castle Ravenloft Board Game Nightfall Rex: Final Days of an Empire Theseus: The Dark Orbit Star Wars: Imperial Assault Minerva Great Western Trail First Martians: Adventures on the Red Planet Pax Emancipation PARKS Deep Vents Genotype: A Mendelian Genetics Game SPYBAM
13 Planet Steam Age of Conan: The Strategy Board Game Battles of Westeros Ora et Labora Andean Abyss Gearworld: The Borderlands Five Tribes: The Djinns of Naqala Zombicide: Black Plague Evolution: Climate Sagrada Between Two Castles of Mad King Ludwig Horrified Raiders of Scythia Bloodborne: The Board Game Frosthaven
14 Byzanz Terra Prime Warhammer: The Island of Blood King of Tokyo Star Wars: The Card Game Zombicide Season 2: Prison Outbreak Roll for the Galaxy Blood Rage Perdition's Mouth: Abyssal Rift Spirit Island New Frontiers Core Space The Lost Worlds of Josh Kirby Flourish Merchants of the Dark Road
15 Axis & Allies Anniversary Edition Arcana Prêt-à-Porter A Few Acres of Snow Descent: Journeys in the Dark (Second Edition) Dominion: Special Edition Three Kingdoms Redux Raiders of the North Sea Mansions of Madness: Second Edition Charterstone Space Park Amul Eclipse: Second Dawn for the Galaxy Radlands Planet Unknown

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?