arXiv Machine Learning

Biases in Expected Goals Models Confound Finishing Ability

The paper investigates the reliability of Expected Goals (xG) as a measure of finishing skill in soccer, arguing that the common practice of comparing cumulative xG to actual goals is flawed. It presents three hypotheses: high variance and small sample sizes make the deviation metric inadequate, including all shot types can mask true finishing ability, and inherent biases in xG models reduce the apparent gap between expected and actual goals for top finishers. Using an AI‑fairness technique to calibrate xG across player subgroups, the authors demonstrate that standard models underestimate Messi’s goal‑adjusted xG (GAX) by 17% and that his GAX is 27% higher than that of typical elite high‑shot‑volume attackers, revealing him as an even more exceptional finisher than previously thought.

arXiv AI
Jul 17

SportD: Can VLMs Physically Strategize?

arXiv:2607. 14616v1 Announce Type: new Abstract: Vision--language models have become increasingly capable of interpreting visual scenes, but it remains unclear whether they can use information to make strategically effective decisions.

By Jasin Cekinmez, Addison J. Wu, Haotian Xia, Akshaya Bharadhwaj, Anay Putty, Anirudh Ravishankar, Jaewoong Lee, Jinglin Xiao, Kyumin Andrew Shim, Mishika Ahuja, Nisarga Patil, Leo Liu, Zhuohan Liu, Weining Shen
arXiv Machine Learning
Sep 10

A Statistical and Machine Learning Framework for Quantifying Offensive Impact in Professional Box Lacrosse

The paper presents a statistical and machine‑learning framework for estimating expected goals (xG) and attributing offensive involvement in professional box lacrosse. Using 1,006 manually annotated shot attempts from 13 Rochester Knighthawks games, the authors evaluate logistic regression, random forest, and extremely randomized trees, finding that a contextual baseline random forest achieves the lowest log loss and Brier score. They also introduce a shot‑based expected assist metric and an exploratory expected pick value (xPV) metric, noting that xPV’s magnitude is indistinguishable from noise but shows a directional pattern in permutation tests.

By Robert Jimerson Jr
arXiv AI
Aug 20

Grouping the Stochastic Machine: Precision, Not Capability, as the Frontier Metric for AI Systems

The article argues that for frontier language models, precision—how consistently outputs cluster around the target—should be the key metric rather than capability, which measures average performance. It proposes a simple, non‑circular method to quantify precision by repeatedly scoring deterministic tasks and computing outcome consistency, and demonstrates how this metric can guide decisions about model improvements. The study shows that precision can reveal whether failures are due to systemic misalignment or random noise, and that real‑world measurement is more valuable than rule‑based benchmarks.

By George Andrikopoulos