POSITIONING DECISIONS USING WEARABLES · USING WEARABLES: SOME INSIGHTS FROM THE...
Transcript of POSITIONING DECISIONS USING WEARABLES · USING WEARABLES: SOME INSIGHTS FROM THE...
POSITIONING DECISIONS USING WEARABLES:SOME INSIGHTS FROM THE
INVASION-TERITORIAL TEAM SPORTS
Dr Bill Gerrard
Professor of Business and Sports Analytics, University of Leeds
N8 PRP Training SessionLeeds University Business School, 16th May 2018
THE ICE-CREAM SELLER PROBLEM
• Context: sunbathers equally spaced along beach; same brand of ice cream sold at same price by both ice-cream sellers
• Positioning problem: where will the two ice-cream sellers position themselves?
THE ICE-CREAM SELLER PROBLEM: PREDICTED OUTCOME
• Predicted outcome: both ice-cream sellers will position themselves in the centre of the beach
• Rationale: only differentiator is distance; incentive for each seller to set up next to each other to grab all the market on one side and share the market on the other side
THE ICE-CREAM SELLER PROBLEM: BEHAVIOUR DYNAMICS
25%25%25% 25%
25%75%
50% 50%
POLITICAL ELECTIONS OFTEN INVOLVE THE SAME POSITIONING LOGIC
THE POLITICAL LANDSCAPE
LEFT CENTRE RIGHT
SqueezedOut
THE POSITIONING DECISION
• Positioning decision: choosing how to optimally
allocate people/things/activities within a specified
space
• Three components in all positioning positions:
- Objective: what are you trying to achieve?
- Context: the relationship between positioning and
outcomes
- Constraints: space; resources
POSITIONING: DIFFERENT CONTEXTS BUT OFTEN A COMMON SOLUTION
• Positioning decisions occur in very different contexts:
- Economics – product positioning
- Politics – electoral positioning
- Geography – locations of cities, towns, villages
- Military conflicts – deployment of military forces
- Invasion-territorial team sports – game tactics
- Policing – what are your positioning decisions?
• But often share a common solution
Optimal Positioning = Median Location
CENTRAL LOCATION THEORY
• Central location theory = spatial
theory in urban geography
• Attempts to explain the reasons
behind the patterns of
distribution, size and numbers of
cities, towns and villages
• Key idea: think of space as
consisting of a series of hexagons
at different levels
ANALYSING SPACE - THINK HEXAGONS NOT CIRCLES OR SQUARES!!!
Why are hexagons the best unit for spatial analysis?
Circles: equi-distant from centre to edge but overlap/leave gaps
Squares: nest together without gaps/overlaps but edges not equi-
distant from centre
Hexagons: nesting property and better approximation to equi-
distance property of circles
THE IMPORTANCE OF SPACE IN TEAM SPORTS
• Invasion-territorial team sports: various codes of
football, rugby, hockey and basketball
• Essence of invasion-territorial sports:
THE CONTROL OF SPACE THROUGH THE
TACTICAL COORDINATION OF PLAYERS
• Spatial dimension is crucial to producing
performance analytics that supports coaching
decisions effectively
THE DIFFERENT LEVELS OF SPATIAL ANALYTICS
Level 3: Trajectory Data
Level 2: X,Y Event Data
Level 1: Zoned Frequency Data
GPSVideo Tracking
Video Analysis(Pitch Grid)
Video Analysis(Pitch Map)
LEVEL 1: EXIT PLAY IN RUGBY UNION
Aviva Premiership Final, May 2015
Bath 16 – 28 Saracens (HT 3 – 25)
• Frequency data indicates that a key factor in Bath’s defeat was their high number of turnovers conceded
• But it is only zoned data that provides a real tactical understanding
• Lesson: too many ball-in-hand plays in own half can be dangerous
Source: Opta data
LEVEL 2: AVERAGE PLAYER POSITION IN FOOTBALL
• Average position calculated based only on player actions
• Example: Ajax , vs AZ, Eredivisie R25, 2015/16, 0 – 60 mins (before substitutions)
LEVEL 3: WEARABLES IN ELITE TEAM SPORTS
LEVEL 3: WEARABLE OUTPUTS –LOCATION; DISTANCE; SPEED
LEVEL 3: MEASURING DEFENSIVE STRETCH IN BASKETBALL
• Basketball analytics is most advanced in analysing space
• CHAD (convex hull area of defence) provides a measure of
defensive stretch
• Allows quantification of impact of “floor-spacers” on attacking
team who stretch opposition defences (i.e. CHAD)
CHAD
Space to be attacked Space to be
created
LEVEL 3: POSITIONING ALGORITHM FOR DEFENDING IN FOOTBALL
• Blue Squares = team in
possession
• Blue Circle = player with
ball
• Black Diamonds =
defending team
• GKs excluded
• Positioning decision involves weighting demands to cover space, opposing players and the ball
• Algorithm currently can give too much weight to covering space in some situations
• Arrows indicate coaching interventions to adjust positioning decision
POLICING AND POSITIONING
•What are your positioning decisions?