Key Concepts / Stroke Metrics

Stroke Metrics

Every player has a unique stroke technique, which varies across stroke classes and play conditions. CueMate computes metrics to help analyze various attributes useful for training and performance.

What Determines the Quality of Strokes and Shots?

Ultimately, the purpose of strokes is to produce outcomes that create shots for the game.

The quality of these outcomes is determined by many factors, including:

  • Anticipation of the incoming ball speed, spin, and its ground impact.
  • Anticipation of the strike and shot target.
  • Movement and stroke preparation, including positioning and stance, influence the impact point and strike zone.
  • Stroke technique, including the shape or form of the stroke.

As you can see, the stroke technique represents only one part of the overall out come process.

With a racket sensor, not all of these variables can be precisely measured, but with the right models, it is possible to estimate a sufficient set of features to diagnose and train fundamental aspects.

Recall that the strokes are organized into classes. This makes it possible to use statistics, i.e., combine many strokes of the same type, to get a more precise understanding of technique and skills.

[Diagram of Technique, Conditions, and Outcomes?]

Stroke Metrics

The following describes the scope of stroke metrics.

Metrics Organization

The stroke metrics are organized in the following five categories:

  • Stroke Primary Outcomes: the ball spin and speed.
  • Strike Quality Metrics: the sweet spot %, impact point, impact variability, and impact timing.
  • Stroke TechniqueMetrics.
  • Stroke Physical Performance.
  • Stroke Coefficients.

Metrics provide objective ways to assess the key features needed for movement skills and performance and, therefore, provide the foundation for deliberate training.

Note: See the dedicated Metrics section for more details about the metrics.

Scores

The metrics are combined under Class Scores to help with the assessment and diagnostics. As shown here, a particular:

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Note that iCueMotion is continuously developing new metrics based on its research. These are the primary ones used in its CueMate system.

#1 Stroke Primary Outcome Metrics

The results produced by a stroke class in the repertoire:

  • Ball speed
  • Ball spin

#2 Strike Quality Metrics

The quality of your ball strike:

  • Sweet spot percentage:the percentage of ball strikes within the racket sweet spot area.
  • Impact Timing:timing of the racket's forward swing relative to the ball strike.
  • Impact precision: the variability of the ball strike location on the racket.

The quality of the ball strike is primarily influenced by the player's ability to anticipate the ball strike, the timely stroke preparation, and the timing of the forward stroke acceleration.

#3 Stroke Technique Metrics

The stroke technique metrics measure attributes of the movement and racket used for a stroke class to produce primary out comes and control the ball on the court. Example include:

  • Smoothness: the continuity of the stroke movement.
  • Racket head speed.
  • Forward-swing type: the shape of the swing.
  • Racket drop: angle of attack of the swing path relative to the horizontal.
  • Racket face openness: the direction the racket head is pointed before the forward swing phase.

#4 Stroke Physical Performance

The physical characteristics of the stroke, including:

  • Power
  • Energy

#5 Stroke Coefficients

Coefficients measure the efficiency of your strokes in producing outcomes. Including:

  • The spin coefficient measures the efficiency of your technique in producing spin.
  • Speed coefficient measures the efficiency of your technique in imparting speed on the ball.
  • The spin-speed coefficient measures the ability to produce both spin and speed.
Learn More About Metrics

 Key Concepts / Stroke Metrics