mxx1's avatar

xG

xG in football is “expected goals”.

When a player takes a shot from circumstances where goals have been scored in the past, xG is assigned by asking what fraction of those shots went in, historically?

Inputs include:
• Distance from goal.
• Angle to goal.
• Whether the shot was with the foot, head or another body part.
• Type of assist, such as through-ball, cross, cut-back or rebound.
• Whether it was a one-on-one.
• Whether the shot followed a set piece or open play.
• Position and sometimes movement of defenders and goalkeeper, if the data provider has tracking data.
• Whether the player was under pressure.
• Whether the shot was one touch or after controlling the ball.

During a game a human data analyst determines that an event was a possible shot on goal. Then the automated camera and computer system applies the model to produces a probability of a goal from that position between 0 and 1.

All these scores are summed up for the whole game and thereby each team gets a total xG for the game.

The quality of the team effort is basically a measure of xG versus actual goals scored.

So, I’m suggesting xG for life, based on these core outcomes:

• Sex
• Money
• Power
• Fame
• Babies
• Envious activities
• Shelter with a roof,

and anything else you care to add

Each action in real life can be assessed as a potential “shot on goal”. Historical data is used to estimate the most likely favourable outcome that an action taken under comparable circumstances produces, normalised to unity.

It’s a measure of efficiency. A score of 0.5 means a person is average and therefore roughly 50% efficient at converting available life opportunities into the relevant outcomes. A score of 1 would represent perfect conversion efficiency and 0 would represent no conversion.

Because it’s a measure of efficiency rather than achievement, a billionaire who inherits everything could have an enormous amount of money but mediocre money-xG efficiency. Someone starting with very poor opportunities and ending moderately wealthy could have a much higher score.