The Wall Street Journal's interactive graphics desk, led by senior news apps developer Chris Canipe, launched an app ahead of the World Cup's knockout stages to visualize penalty kick tendencies of top players. The project was inspired by Geoff Foster's video on saving penalty kicks and Matthew Futterman's focus on the topic, aiming to show how players distribute their kicks and the likelihood of scoring.
The project relied on detailed X-, Y-, and Z-coordinates for penalty kicks provided by Opta, a soccer data provider. This data, delivered in spreadsheets, included the end position of goals or misses. While Opta's data was highly detailed, the WSJ team had to correct initial errors, such as reversed Y-positions, by manually reviewing videos of kicks, acknowledging the inherent risk and room for human error in hand-coded data.
The interactive utilized a "small multiples" design approach, built with D3, to allow users to compare multiple players side-by-side, such as Messi, Hulk, and Cavani, especially those with a significant number of kicks. The interactive was restricted to two players per team in the round of 16 due to data limitations, as not all players have extensive penalty kick histories. The app was highly successful upon its launch, generating significant traffic and making the WSJ seem prescient when the first game after its release ended in a shootout.
The interactive revealed key insights into penalty kicks: overall success rates are about 78%, increasing by 7% if kicked to the middle. However, most players rarely aim for the middle of the goal, instead trending left or right. The project, though requiring significant effort to narrow down its focus, demonstrated the lasting interest in World Cup content and the power of data visualization in sports analysis, drawing parallels to baseball's analysis of player patterns.
