Christopher Lai

I am a first-year Master's student in Robotics at the University of Pennsylvania, currently working with Professor Rahul Mangharam in xLab (Safe Autonomous Systems Lab). Previously, I received my B.S. in Computer Engineering from UC Santa Barbara, where I conducted research in computer vision and multimodal learning in the Computer Vision Research Lab led by Yuan-Fang Wang, and the Four Eyes Lab under Tobias Höllerer.

I'm always happy to connect about computer vision, robotics, and interesting engineering opportunities.

Email  /  GitHub  /  Google Scholar  /  LinkedIn

profile photo

Technical Interests

I'm interested in computer vision, multimodal perception, and learning-based autonomy, building systems that understand dynamic environments and support reliable decisions. My interests span geometric vision and scene understanding, visual tracking and motion prediction, and relational and temporal learning for multi-agent interactions. I'm also interested in the robustness, observability, and evaluation of perception systems, particularly as they connect to decision-making in robotics and autonomous driving.

Projects

AV Perception TRACE
AV Perception TRACE
Autonomous Driving · Perception & Evaluation

Built an interpretable perception-to-decision pipeline on nuScenes using structured reasoning traces, learned factor models, and Understand-Decide-Verify (UDV) evaluation to analyze autonomous decision-making and failure modes.

Allez Go — Multimodal Fencing Analysis
Allez Go — Multimodal Fencing Analysis
Sports Analytics · Multimodal Action Recognition

Explored fine-grained fencing action recognition using skeletal pose and audio features, combining multimodal representations to better understand athlete movements and interactions.

Research

project image

DeepSport: A Multimodal Large Language Model for Comprehensive Sports Video Reasoning via Agentic Reinforcement Learning


Junbo Zou, Haotian Xia, Zhen Ye, Shengjie Zhang, Christopher Lai, Vicente Ordonez, Weining Shen, Hanjie Chen
Preprint
arxiv

We introduce DeepSport, the first end-to-end trained MLLM framework designed for multi-task, multi-sport video understanding, featuring active iterative reasoning with a specialized frame-extraction tool and achieving state-of-the-art performance on sports video reasoning tasks.
project image

SportR: A Benchmark for Multimodal Large Language Model Reasoning in Sports


Haotian Xia, Haonan Ge, Junbo Zou, Hyun Woo Choi, Xuebin Zhang, Danny Suradja, Botao Rui, Ethan Tran, Wendy Jin, Zhen Ye, Xiyang Lin, Christopher Lai, Shengjie Zhang, Junwen Miao, Shichao Chen, Rhys Tracy, Vicente Ordonez, Weining Shen, Hanjie Chen
ICLR 2026 (Poster)
arxiv

We introduce SportR, a multi-sports benchmark designed to train and evaluate MLLMs on fundamental reasoning required for sports intelligence, featuring images and videos with progressive reasoning tasks.
project image

FACTS: Fine-Grained Action Classification for Tactical Sports


Christopher Lai, Jason Mo, Haotian Xia, Yuan-fang Wang
Preprint
arxiv

We introduce FACTS, a novel transformer-based approach for fine-grained action recognition in fast-paced, close-combat sports that processes raw video data directly, achieving state-of-the-art performance on fencing and boxing actions.
project image

SPORTU: A Comprehensive Sports Understanding Benchmark for Multimodal Large Language Models


Haotian Xia, Zhengbang Yang, Junbo Zou, Rhys Tracy, Yuqing Wang, Chi Lu, Christopher Lai, Yanjun He, Xun Shao, Zhuoqing Xie, Yuan-fang Wang, Weining Shen, Hanjie Chen
ICLR 2025 (Poster)
arxiv

We introduce SPORTU, a comprehensive benchmark designed to assess Multimodal Large Language Models (MLLMs) across multi-level sports reasoning tasks, featuring both text-based rule comprehension and video-based action recognition components.

Industry Experience

Amazon Web Services OpenSearch Machine Learning Commons  ·  design doc  ·  code May–Aug 2025
Blue Origin Machine Learning & Data Science Enablement Jan–Apr 2025
NASA Goddard Lunar Navigation Maps  ·  code Jul–Sep 2024

Website design adapted from Leonid Keselman's Jekyll fork of Jon Barron's website. Last updated October 2026