RallyComparator: visual comparison of the multivariate and spatial stroke sequence in table tennis rally

Table tennis matches consist of many stroke sequences where two players hit the ball interactively and consecutively until one fails to hit the ball. Players usually employ many complicated playing techniques at each stroke in highly antagonistic, variable, and flexible matches. In-depth comparative analyses of players' stroke sequences are necessary to obtain insights into the technical playing patterns of players. Experts commonly use spreadsheets to browse and compare strokes one by one, and this process is tedious and prone to errors. Statistical analyses are limited to well-defined patterns (e.g., value distribution and relation significance) and fail to present complex and peculiar patterns. We collaborated with experts to dig out soft patterns of stroke sequences and proposed a novel interactive visualization system to present and compare the patterns. The main visualization challenge is to display the multivariate stroke sequence and the spatial variation patterns. We designed a glyph-based pattern view to solve the challenge. These comprehensible visualizations and coordinated views in the system allow efficient comparative analysis of stroke sequence patterns and are highly commended by domain experts, who have identified several new and interesting patterns using the system. We demonstrated the effectiveness and usability of the visualization system through case studies with table tennis experts. .

Automated summary

Table tennis matches involve complex and variable stroke sequences, requiring in-depth analysis of players' technical playing patterns. Traditional analytical methods are cumbersome and limited, prompting the proposal of a novel visualization system to assist experts in discovering new and interesting stroke sequence patterns.