# Recognizing Events in Spatiotemporal Soccer Data
## 3 Experimental Setup  
As noted by [PERSON] et al. [23], it is difficult to compare results obtained in different research works due to differences in experimental settings, types of events, and used datasets. Therefore, details of the experimental setup are essential, as they might have a significant impact on results. In addition, details of our datasets show what can be expected from acquired player tracking data in typical cases. We work with two distinct spatiotemporal soccer datasets, obtained by tracking players with several fixed cameras, and subsequent digitization of recorded video streams (see Table 1). The first dataset (\"DS\") represents five full matches of the Japanese J1 league captured in 2011. These recordings accurately capture the course of the game, and even significant pauses within the game are not removed. Player tracking is accurate in general, but occasional jitters do occur, so one may observe sudden jumps of player and ball objects. Such situations usually happen when many players are close to each other, particularly during free and corner kicks. Each captured frame is annotated with two additional binary attributes: _Ball owning team_ (home/away) and _ball status_ (dead/alive), so we know which team is the attacker, and whether the game is stopped by the referee. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \begin{tabular}{c} **Name** \\ **(Provider)** \\ \end{tabular} & **Sequences** & **Total Time** & \begin{tabular}{c} **Frames** \\ **per sec** \\ \end{tabular} & \multicolumn{2}{c}{**Additional Features**} \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} DS \\ (Data Stadium) \\ \end{tabular} } & \multirow{2}{*}{5} & \multirow{2}{*}{320 min (5 games)} & \multirow{2}{*}{25} & \multirow{2}{*}{**_ball owning team_ and _ball status_ fields} \\  & & & & tracking data of a referee \\ \cline{1-1} \cline{4-4}  & & & \(z\)-coordinate of the ball \\ \cline{1-1} \cline{4-4}  & & & & timewasting periods are included \\ \cline{1-1} \cline{4-4}  & & & & player names and roles are known \\ \hline \multirow{4}{*}{
\begin{tabular}{c} ST \\ (Stats Perform) \\ \end{tabular} } & \multirow{2}{*}{7578} & \multirow{2}{*}{2220 min (45 games)} & \multirow{2}{*}{10} & \multirow{2}{*}{ attacking team is always on the left} \\  & & & & no “dead” segments (stopped by referee) \\ \cline{1-1} \cline{4-4}  & & & & teams are always complete (11 players) \\ \cline{1-1} \cline{4-4}  & & & & player data is anonymized \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Experimental datasets. The second dataset (\"ST\") [5] consists of a large number of short game episodes (from 5 to 150 s), taken from recent matches played in a top European league. An episode starts when a certain team gets possession of the ball, and ends when the team loses control of the ball. Player movements are smooth, and jitters are rare. However, this dataset has few shots on goal and few unsuccessful passes. Occasionally the outcome of the attacking team's last action can be analyzed, but episodes ending with the ball still in the air are also common. The ST dataset is organized as a collection of independent sequences, representing game episodes. Each sequence contains a list of frame objects, organized as follows:  
\[(G_{x},G_{y})(P1_{x},P1_{y})\ldots(P10_{x},P10_{y})(G^{\prime}_{x},G^{\prime}_ {y})(P1^{\prime}_{x},P1^{\prime}_{y})\ldots(P10^{\prime}_{x},P10^{\prime}_{y}) (B_{x},B_{y}).\]  
A frame starts with the \((x,y)\) coordinates of the goalkeeper of the team currently possessing the ball. After the goalkeeper coordinates, the coordinates of the field players of the same team are listed. There is no predefined order of players in this list, but the same order is preserved throughout the episode, so it is possible to trace the trajectory of a certain player in the given episode. The total number of field players is always 10, which means that only episodes featuring complete teams are included in the dataset. The next block describes the opposing team in the same manner. Finally, there are \((x,y)\) coordinates of the ball.