[Retracted] The Selecting Optimal Ball-Receiving Body Parts Using Pose Sequence Analysis and Sports Biomechanics

Table 3

Three kinds of ML.

Serial number	Name		A brief introduction
1	Supervised learning (with data labels)	Classification	Machines are trained to divide a group into specific classes
		Regression	The machine uses previous (labeled) data to predict future events
2	Unsupervised learning (no data labels)	Clustering	It is used to cluster data according to attributes and behavior objects and then apply the clustered data to targeted construction schemes
		Dimensionality reduction	It reduces the variables of the dataset by finding common ground. Most big data visualization uses dimensionality reduction to identify trends and rules
3	Reinforced learning		It uses the personal history and experience of the machine to make decisions. Unlike supervised and unsupervised learning, reinforced learning does not involve providing “correct” answers or outputs. Instead, it focuses only on performance