journal article·2024-11-12Open access

Beyond xG: A Dual Prediction Model for Analyzing Player Performance Through Expected and Actual Goals in European Soccer Leagues

Davronbek Malikov, Jaeho Kim

Applied Sciences· Volume 14· Issue 22

Abstract

Soccer is evolving into a science rather than just a sport, driven by intense competition between professional teams. This transformation requires efforts beyond physical training, including strategic planning, data analysis, and advanced metrics. Coaches and teams increasingly use sophisticated methods and data-driven insights to enhance decision-making. Analyzing team performance is crucial to prepare players and coaches, enabling targeted training and strategic adjustments. Expected goals (xG) analysis plays a key role in assessing team and individual player performance, providing nuanced insights into on-field actions and opportunities. This approach allows coaches to optimize tactics and lineup choices beyond traditional scorelines. However, relying solely on xG might not provide a full picture of player performance, as a higher xG does not always translate into more goals due to the intricacies and variabilities of in-game situations. This paper seeks to refine performance assessments by incorporating predictions for both expected goals (xG) and actual goals (aG). Using this new model, we consider a wider variety of factors to provide a more comprehensive evaluation of players and teams. Another major focus of our study is to present a method for selecting and categorizing players based on their predicted xG and aG performance. Additionally, this paper discusses expected goals and actual goals for each individual game; consequently, we use expected goals per game (xGg) and actual goals per game (aGg) to reflect them. Moreover, we employ regression machine learning models, particularly ridge regression, which demonstrates strong performance in forecasting xGg and aGg, outperforming other models in our comparative assessment. Ridge regression’s ability to handle overlapping and correlated variables makes it an ideal choice for our analysis. This approach improves prediction accuracy and provides actionable insights for coaches and analysts to optimize team performance. By using constructed features from various methods in the dataset, we improve our model’s performance by as much as 12%. These features offer a more detailed understanding of player performance in specific leagues and roles, improving the model’s accuracy from 83% to nearly 95%, as indicated by the R-squared metric. Furthermore, our research introduces a player selection methodology based on their predicted xG and aG, as determined by our proposed model. According to our model’s classification, we categorize top players into two groups: efficient scorers and consistent performers. These precise forecasts can guide strategic decisions, player selection, and training approaches, ultimately enhancing team performance and success.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Sports Analytics and Performance · Sports Performance and Training · Sport Psychology and Performance

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Department of AI Convergence Engineering, Gyeongsang National University (GNU), Jinjudaero 501, Jinjusi 52828, Republic of Korea

Department of AI Convergence Engineering & Department of Software Engineering, Gyeongsang National University (GNU), Jinjudaero 501, Jinjusi 52828, Republic of Korea

Funding

Gyeongsang National University

References (39)

Show source-provided references
1. Fédération Internationale de Football Association (FIFA) (2023, December 13). More than Half the World Watched Recordbreaking 2018 World Cup. p. e0282295. Available online: https://inside.fifa.com/tournaments/mens/worldcup/2018russia/media-releases/more-than-half-the-world-watched-record-breaking-2018-world-cup.
2. Wood, R. (2024, January 20). World’s Most Popular Sports by Fans. Available online: https://www.topendsports.com/world/lists/popular-sport/fans.htm.
3. News, S. (2024, January 20). Premier League Central Payments to Clubs 2022/23. Available online: https://www.premierleague.com/news/3676561.
4. Mead, J., O’Hare, A., and McMenemy, P. (2023). Expected goals in football: Improving model performance and demonstrating value. PLoS ONE, 18.10.1371/journal.pone.0282295 ↗
5. Zeng, Z., and Pan, B. (2021, January 28–29). A Machine Learning Model to Predict Player’s Positions based on Performance. Proceedings of the icSPORTS, Valletta, Malta.
6. Pinnacle (2023, December 01). Understanding the Limitations of Expected Goals. Available online: https://www.pinnacle.com/betting-resources/en/soccer/understanding-the-limitations-of-expected-goals/k4gjclwx3vs6mwvk.
7. Charles Reep: A major influence on British and Norwegian football10.1080/714004854 ↗
8. Charles Reep (1904–2002): Pioneer of notational and performance analysis in football10.1080/026404102320675684 ↗
9. Bening, S. (2023, November 05). Data Science and Soccer: The xG Phenomenon. Available online: https://annals.yonsei.ac.kr/news/articleView.html?idxno=10988.
10. Statsperform (2023, October 10). EXPECTED GOALS IN CONTEXT. Available online: https://www.statsperform.com/resource/expected-goals-in-context/.
11. Anzer, G., and Bauer, P. (2021). A goal scoring probability model for shots based on synchronized positional and event data in football (soccer). Front. Sport. Act. Living, 3.10.3389/fspor.2021.624475 ↗
12. Eggels, H., Van Elk, R., and Pechenizkiy, M. (2016, January 19). Explaining soccer match outcomes with goal scoring opportunities predictive analytics. Proceedings of the 3rd Workshop on Machine Learning and Data Mining for Sports Analytics (MLSA 2016), Riva del Garda, Italy. Available online: https://ceur-ws.org/.
13. Lucey, P., Bialkowski, A., Monfort, M., Carr, P., and Matthews, I. (2024, January 24). Quality vs Quantity: Improved Shot Prediction in Soccer Using Strategic Features from Spatiotemporal Data. Available online: https://www.sloansportsconference.com/research-papers/quality-vs-quantity-improved-shot-prediction-in-soccer-using-strategic-features-from-spatiotemporal-data.
14. An examination of expected goals and shot efficiency in soccer10.14198/jhse.2017.12.Proc2.05 ↗
15. Spearman, W. (2018, January 23–24). Beyond expected goals. Proceedings of the 12th MIT Sloan Sports Analytics Conference, Boston, MA, USA.
16. Plus–minus player ratings for soccer10.1016/j.ejor.2019.11.026 ↗
17. Madrero Pardo, P. (2020). Creating a Model for Expected Goals in Football Using Qualitative Player Information. [Master’s Thesis, Universitat Politècnica de Catalunya].
18. Effects of positional variables on shooting outcome in elite football10.1080/24733938.2017.1383628 ↗
19. Dealing with randomness in match outcomes: How to rethink performance evaluation in European club football using expected goals10.1177/1527002519897962 ↗
20. Predicting football results using Bayesian nets and other machine learning techniques10.1016/j.knosys.2006.04.011 ↗
21. Tait, J. (2024, March 14). Just How Accurate is Expected Goals?. Available online: https://jacktait.substack.com/p/just-how-accurate-is-expected-goals.
22. Garratt-Stanley, F. (2024, March 14). What is Expected Goals (xG)?. Available online: https://jobsinfootball.com/blog/what-is-expected-goals-xg/.
23. Statsbomp (2024, March 14). What Are Expected Goals (xG)?. Available online: https://statsbomb.com/soccer-metrics/expected-goals-xg-explained/.
24. Opta Analyst (2023, December 10). Opta Analyst: Expected Goals (xG). Available online: https://theanalyst.com/eu/2023/08/what-is-expected-goals-xg/.
25. Tweedale, A. (2023, December 10). Expected Goals: Explained. Available online: https://www.coachesvoice.com/cv/expected-goals-xg-explained/.
26. Chappas, C. (2023, December 15). Comparing Actual and Expected Goals. Available online: https://statsbomb.com/articles/soccer/comparing-actual-and-expected-goals/.
27. Statistics (2024, November 10). 2022/23 in numbers: Who did best for Expected Goals?. Available online: https://www.premierleague.com/news/3533343.
28. Webster, E. (2023, September 15). Soccer Analytics. Available online: https://github.com/eddwebster/football_analytics/tree/master/data/understat/raw/metadata.
29. (2023, September 15). Website:Understat Professional Soccer Website. Available online: https://understat.com/.
30. Scikit (2024, February 07). Machine Learning in Python. Available online: https://scikit-learn.org/stable/.
31. Pandas (2024, February 07). Manipulation with Python. Available online: https://pandas.pydata.org/.
32. Numpy (2024, February 07). Statistics with Python. Available online: https://numpy.org/.
33. Seaborn (2024, February 07). Statistical Data Visualization in Python. Available online: https://seaborn.pydata.org/.
34. Matplotlib (2024, February 07). Visualization with Python. Available online: https://matplotlib.org/.
35. UEFA (2023, December 15). Club Stats. Available online: https://www.uefa.com/uefachampionsleague/statistics/clubs/.
36. Statista (2023, December 15). Average Attendance of the Big Five Soccer Leagues in Europe from 2013/14 to 2022/23, by League. Available online: https://www.statista.com/statistics/261213/european-soccer-leagues-average-attendance/.
37. (2024, March 12). Jannik Lindner Statistics About the Most Important Position in Soccer. Available online: https://gitnux.org/most-important-position-in-soccer/.
38. Brownlee, J. (2024, June 10). A Gentle Introduction to k-fold Cross-Validation. Available online: https://machinelearningmastery.com/k-fold-cross-validation/.
39. Kohavi, R. (1995, January 20–25). A study of cross-validation and bootstrap for accuracy estimation and model selection. Proceedings of the 14th International Joint Conference on Artificial Intelligence (IJCAI), Montreal, QC, Canada.