Predicting Board Game Collections

ZeeGarcia’s Collection

Author

Phil Henrickson

Published

9/24/24

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
ZeeGarcia ever_owned 1891
ZeeGarcia own 517
ZeeGarcia rated 2449

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
ZeeGarcia -3500-2020 train 24172 346
ZeeGarcia 2021-2022 valid 9804 93
ZeeGarcia 2023-2028 test 9021 78

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
ZeeGarcia glmnet resamples binary 0.057 0.889 0.164
ZeeGarcia glmnet test binary 0.045 0.876 0.076
ZeeGarcia glmnet valid binary 0.042 0.898 0.148

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 Call of Cthulhu: The Card Game Mr. Jack in New York Glen More The Castles of Burgundy Libertalia Legacy: The Testament of Duke de Crecy Imperial Settlers 7 Wonders Duel Scythe Circle the Wagons Root Cthulhu: Death May Die Pandemic Legacy: Season 0 Arkham Horror: The Card Game (Revised Edition) Libertalia: Winds of Galecrest
2 Roll Through the Ages: The Bronze Age Dice Town 7 Wonders Eminent Domain Robinson Crusoe: Adventures on the Cursed Island Lewis & Clark: The Expedition Blue Moon Legends Mission: Red Planet (Second Edition) When I Dream Pandemic Legacy: Season 2 Château Aventure Wingspan Dragomino Night of the Living Dead: A Zombicide Game Endless Winter: Paleoamericans
3 A Game of Thrones: The Card Game Alea Iacta Est Mr. Jack Pocket Puerto Rico Shadows over Camelot: The Card Game Eight-Minute Empire: Legends Madame Ching Pandemic Legacy: Season 1 Conan Gloomhaven Micropolis Ishtar: Gardens of Babylon Gloomhaven: Jaws of the Lion Agropolis Long Shot: The Dice Game
4 Ghost Stories Macao Earth Reborn Mundus Novus Il Vecchio Longhorn Port Royal Raptor Arkham Horror: The Card Game Stop Thief! Rising Sun Aftermath Via Magica Sobek: 2 Players Frosthaven
5 Byzanz Long Shot 51st State Takenoko Seasons Bruges Five Tribes: The Djinns of Naqala Blood Rage Hit Z Road Pandemic: Rising Tide Everdell Deep Blue Puerto Rico Sleeping Gods Sea Salt & Paper
6 Bushido: Der Weg des Kriegers The Adventurers: The Temple of Chac Merchants & Marauders The Lord of the Rings: The Card Game Eight-Minute Empire Rise of Augustus Pandemic: The Cure Elysium Lorenzo il Magnifico My Little Scythe Zombicide: Green Horde Naga Raja Hues and Cues Flourish 1001 Islands
7 Witch of Salem Chronicle Grimoire Friday Okiya Glass Road Don't Mess with Cthulhu Viticulture Essential Edition Islebound SOW Fall of Rome Marvel Champions: The Card Game Viscounts of the West Kingdom Zombicide: 2nd Edition Knight Fall
8 Snow Tails Endeavor GOSU Elder Sign Ginkgopolis Eldritch Horror La Isla Trambahn Reign of Cthulhu The Castles of Burgundy: The Dice Game A Song of Ice & Fire: Tabletop Miniatures Game – Stark vs Lannister Starter Set Herbaceous Sprouts Detective: A Modern Crime Board Game – Season One Run Run Run! Hunch!
9 Pandemic Arcana DungeonQuest (Third Edition) Ora et Labora Antartik Skull King Desperados of Dice Town Between Two Cities Mansions of Madness: Second Edition Charterstone Finca Conspiracy: Abyss Universe Unmatched: Little Red Riding Hood vs. Beowulf Ankh: Gods of Egypt Amsterdam
10 Piece o' Cake Small World The Speicherstadt Witty Pong Descent: Journeys in the Dark (Second Edition) SOS Titanic Dragon Run GEM Dice Stars Lovecraft Letter Treasure Island Draftosaurus Endangered Marvel United: X-Men Tribes of the Wind
11 Senji Shipyard Mystery Express PRRRT... Keyflower City of Iron Legendary Encounters: An Alien Deck Building Game Steampunk Rally Kanagawa First Martians: Adventures on the Red Planet Space Park Ice Team Dune: Imperium Cestou necestou The Guild of Merchant Explorers
12 Stone Age Cyclades Tikal II: The Lost Temple The Blue Lion Mice and Mystics Bora Bora Artifacts, Inc. Codenames Pocket Madness BOO Sprawlopolis Ohanami Dwellings of Eldervale Cascadia Wildtails: A Pirate Legacy
13 Ticket to Ride: The Card Game Martinique Luna Summoner Wars: Master Set Neuroshima: Convoy The Little Prince: Make Me a Planet Abyss Arboretum A Game of Thrones: Hand of the King Legendary Forests Century: Eastern Wonders Tapestry Roland Wright: The Dice Game Imperium: Classics Marvel Zombies: Heroes' Resistance
14 Penguin Party Vampires of the Night Haggis The City Suburbia Caverna: The Cave Farmers Orongo Mysterium The Castles of Burgundy: The Card Game LYNGK Arkham Horror (Third Edition) Queenz: To Bee or Not to Bee Pendulum Explorers Wayfarers of the South Tigris
15 Red November Dominion: Intrigue Funfair Dr. Shark Escape: The Curse of the Temple Cinque Terre AquaSphere The Little Prince: Rising to the Stars Inis Arkham Noir: Case #1 – The Witch Cult Murders Decrypto Fantastic Factories Tidal Blades: Heroes of the Reef Key Pai Sho Gateway Island

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?