Age Adjusted

Used predominantly when analysing youth football, it is a metric that has been normalised to reflect the age of the player.

Rob Vollman, a hockey analytics writer for ESPN & the author of Stat Shot:  The Ultimate Guide to Hockey Analyticsoutlined his process of using age-adjusted stats to identify the best young prospects in junior hockey.

Jason of The Rangers Report used this method here


Converstion Rate

The percentage of a player or team’s shots that beat the keeper


Half Space 


Establishing pass

The pass that led to the secondary assist (the 4th player to touch the ball if you are working backwards from a goal).


Fenwick

Named after the Calgary Flames blogger Matt Fenwick – who first started applying the stat to is coverage of shot totals.
It simply is a tally of total shots (either on target or off target) excluding blocked shots. The idea being that blocking shots is actually a defensive skill, so why punish the defending team by dinging them with a shot against?  In reality, a solid defensive play actually prevented a shot from going on goal.


Key Entries

The number of times a team or player crosses the 18 yard line (if the 18 yard line was across the whole pitch).


Key Pass

A pass (or miss-hit shot) that leads to a shot, including assists.

Other sites have different descriptions for this but we will be using the above description on the site.


NPG
NonPenalty Goals

All goals that didn't come as the direct result of a penalty (rebounded shots count)


Projected Goals

Combining Expected Shot Accuracy with xSh% to basically project how many goals a player should have scored

Jason of The Rangers Report introduced this method here


PAdj –

Possession adjusted

Often used with defensive statistics, these are metrics that have been adjusted to reflect the amount of possession a team has had.


Per 90 or /90 

An alternative to looking at 'Total' stats, Per 90 refers to the number of actions per 90 minutes of playing time. 


Per Possession

Similar to PAdj this is the number of ‘actions’ per time on the ball, sometimes expressed as 'per minute of possession'

Jamie Kilday @FitbaInScotland looked into this method here


r2

R-squared is a statistical measure of how close the data are to the fitted regression line. It is also known as the coefficient of determination, or the coefficient of multiple determination for multiple regression.

The definition of R-squared is fairly straight-forward; it is the percentage of the response variable variation that is explained by a linear model. Or:

R-squared = Explained variation / Total variation

R-squared is always between 0 and 100%:

  • 0% indicates that the model explains none of the variability of the response data around its mean.

  • 100% indicates that the model explains all the variability of the response data around its mean.

In general, the higher the R-squared, the better the model fits your data.

More info here


Regress To The Mean

In statistics, regression toward (or to) the mean is the phenomenon that if a variable is extreme on its first measurement, it will tend to be closer to the average on its second measurement—and if it is extreme on its second measurement, it will tend to have been closer to the average on its first.


Secondary Pass or Secondary Assist

The pass that led to an assist or key pass. (the 3rd player to touch the ball if you are working backwards from a goal).


Scoring Chance

Kicked shots that come from the heart of the penalty area & kicked/headed shots from within the six-yard box.


Sh%

Shooting Percentage

The rate of shots on target that end up beating the keeper for a goal.  It differs from Conversion Rate because that looks at all shots, while Sh% only accounts for shots on target.


xGlossary


xA

Expected Assists - This is equal to the xG of the shot taken from a key pass. e.g. if a shot has an xG of 0.5 then the key pass would have an xA of 0.5.

Other sites have different descriptions for this but we will be using the above description on the site.


xCR

Expected Conversion Rate - This is the same as conversion rate but with the goals replaced with xG


xG

Expected Goals - a figure derived using several variables to judge how likely a shot would have been a goal. Expressed as a decimal xG for a particular shot is always between 0-1 with zero being highly unlikely and one being an absolute certainty.


xGChain

The sum of the xG attributed to a players, Key Passes, Secondary Passes and Establishing Passes


xSAcc

Expected Shooting Accuracy Projects what a player's Shooting Accuracy should have been based on the kinds of shots on target they were getting.


xSh%

Expected Shooting Percentage -  Projects what a player's Shooting Percentage should have been based on the kinds of shots on target they were getting.

Jason of The Rangers Report used this method here