Player Card Explainer

Player Card Contents:

Context: Each card contains the player’s name, the season in question, and the number of minutes the player has played during the league season.

Overall Impact and Overall Impact Component Percentiles:

  • Overall: Overall expected points above replacement (xPAR) percentile. The xPAR metric is an amalgamation of a player’s offense, defense, and shot impact, weighted for the player’s minutes played and the share of their team’s shots taken when the player is on the pitch.
  • Offense Impact: Estimate of how a player impacts his team’s scoring chance creation (expected goals for), in percentile form.
  • Defense Impact: Estimate of how a player impacts the opposition team’s scoring chance creation (expected goals against), in percentile form.
  • Shot Impact: Estimate of how a player’s shooting ability impacts the probability that a given scoring chance results in a goal (shooting outcomes relative to expected goals), in percentile form. For players with an extremely small sample of shots taken, their shot impact is noted as “-,” meaning it is not currently estimated.

Isolated Impact Z-Scores: Estimates presented as z-scores to illustrate their value in relation to the distribution, where a higher z-score indicates a better relative impact.

  • Offense: Estimates of how a player impacts his team’s creation of expected goals and goals, controlling for teammates, opposition, managers, and situation. The expected goals bar includes a 95% confidence interval line, reflecting the bootstrap-produced confidence interval for the Leviathan Isolated Impact model output.
  • Defense: Estimates of how a player impacts the opposition team’s creation of expected goals and goals, controlling for teammates, opposition, managers, and situation. The expected goals bar includes a 95% confidence interval line, reflecting the bootstrap-produced confidence interval for the Leviathan Isolated Impact model output.
  • Shot: Estimates of how a player’s shooting ability impacts the probability that a given shot results in a goal, disaggregated into three major shot situations: shots from open play, direct free kicks, and penalties.

Shot Share, xG Share, and Usage Plots: The values for each player (label and red line) are noted in relation to the distribution of all players in the dataset (grey histogram).

  • Shot Share: (Number of shots taken by the given player)/(Total number of shots generated by the player’s team while the player is on the pitch)
  • xG Share: (Total expected goals value of shots taken by the given player)/(Total expected goals value of all shots generated by the player’s team while the player is on the pitch)
  • Usage: (Total expected goals value of shots taken by the given player + Total expected goals value of shots assisted by the given player)/(Total expected goals value of all shots generated by the player’s team while the player is on the pitch)

Overall xPAR Percentile Plot:

  • Expected points above replacement (xPAR) percentile plotted for the current season, 2020/21, and the three preceding seasons, 2017/18, 2018/19, and 2019/20.

Offense vs Defense vs Shot Plot:

  • Offense impact percentile, defense impact percentile, and shot impact percentile, for applicable players, plotted for the current season, 2020/21, and the three preceding seasons, 2017/18, 2018/19, and 2019/20.

Note on Percentiles: Percentiles are an easy way of showing how each player ranks in comparison to all of the other players in the dataset. For example, a player with an overall impact in the 60th percentile means that they have a greater (better) overall impact than 60% of players in the dataset. An average player would have an overall impact in the 50th percentile, meaning that they are better than 50% of players in the dataset.