The FotMob player rating is calculated based on more than 300 individual stats per player per match from Opta. A match in the per match ratings is any match the participant has been involved in even if he came on as substitute in the last few minutes. A player must have played at least 50% of all matches and at least 90 minutes (for the per 90 stats) to be included in the rankings.

FotMob Rating

Expected goals (or xG for short) is the likelihood that a shot will result in a goal. In other words, a measurement of how good the chance was. A player or team's total xG in a match can give an indication of how many goals they could have expected to score, given the quality and quantity of the chances they created. For each shot, an xG value from 0 to 1 is assigned, with a value of 1 representing a guaranteed goal. So, if a shot has an xG value of 0.4, that means you would expect a goal to be scored from that shot 4 out of 10 times. This is based on the shot angle, distance from goal, type of pass, header or shot, among other factors. So, if a team loses 1-0, but they had an xG of 2.1, you can say they were unlucky to lose, as they could have been expected to score at least 2 goals from the chances they created. More <a href="https://www.youtube.com/watch?v=w7zPZsLGK18&feature=emb_logo">from Opta here</a>.

Expected Goals (xG)

xGOT not only takes into account the quality of the chance, it also measures the quality of the shot. A value is assigned to the goalmouth location where the ball ended up, giving more credit to shots that end up in the corners compared with shots that go straight down the middle of the goal. This model is only for on-target shots given that if you don’t get your shot on target, there's a 0% chance that it will result in a goal. Essentially, xG is a pre-shot model while xGOT is a post-shot model. (Opta)

Expected Goals On Target (xGOT)

Expected assists (or xA for short) is a measurement of the quality of the chance created by a player, based on the likelihood that a pass will become an assist. This means that a pass that puts a forward through on goal will have a higher xA than a pass outside the 18-yard-box, even if both result in assists for the player. It is important to note that the passing player still gets credit for the quality of their pass, whether or not the receiving player is able to convert it into a shot or goal. This means that it is not reliant on the finishing ability of the receiving player, but solely the quality of the pass provided. More <a href="https://www.youtube.com/watch?v=H4kNa1cUvZM&feature=emb_title">from Opta here</a>.

Expected Assists (xA)

Opta: A situation where a player should reasonably be expected to score, usually in a one on one scenario or from very close range when the ball has a clear path to goal and there is low to moderate pressure on the shooter. Penalties are always considered big chances.

Big Chance

The final pass leading to the recipient having an attempt at goal.

Chance created

Opta: A duel is an 1v1 contest between two players of opposing sides in the match. For every Duel Won there is a corresponding Duel Lost depending on the outcome of the contest.

Duel

Opta: This is an attempt by a player to beat an opponent when they have possession of the ball. A successful dribble means the player beats the defender while retaining possession, unsuccessful ones are where the dribbler is tackled.

Dribble

Calculated as xGOT conceded from shots on target faced, minus goals conceded. So it’s a number that shows how many goals the keeper would have expected to concede vs how many he actually conceded. 

Goals Prevented

Opta: This is where a player reads an opponent’s pass and intercepts the ball by moving into the line of the intended pass.

Interception

Opta: This is where a player recovers the ball in a situation where neither team has possession or where the ball has been played directly to him by an opponent, thus securing possession for their team.

Recovery

Opta: A deliberate attempt to score that is on target. Includes all Goals being scored and shots on target saved by the Goalkeeper.
It also includes shots on target that are Blocked by a last line defending player, preventing the ball from entering the Goal.
Also See ‘Shot Off Target.’

Shot on target

Opta: A deliberate attempt to score that misses the target, without contact from a player diverting the ball from on target to off target.
A shot hitting the frame of the Goal is classified as a Shot Off Target unless the ball subsequently enters the net. A Blocked Shot is not classified as a Shot Off Target.
Also see ‘Shot on Target.’

Shot off target

Opta: A Blocked Shot is defined as an attempt to score including:
• An attempt on target Blocked by an outfield player, where other defenders or a Goalkeeper are behind the Blocker.
• Incorporates shots Blocked unintentionally by the shooter’s own teammate.
• Clearances off the line by an opposition player (last line Blocks) are classified as Shots on Target and not as a Blocked Shot.

Blocked shot

Opta defines touches as the “sum of all events where a player touches the ball”. For example, if a player controls the ball, gets it out of his feet, then passes it to a team-mate, that would be one touch.

Touches

The total number of tackles, interceptions, clearances, and blocks a player makes. This is the same metric used in Fantasy Premier League for defenders.

Defensive contributions

The Player Traits chart highlights a player’s statistical strengths and weaknesses, in comparison to similar players. Each stat is adjusted on a per 90 basis and includes matches from the past 365 days. Players are then compared to positional peers from similar leagues, and placed into a percentile ranking. For example, a player with a 90% percentile ranking on Chances Created means that they create more chances than 90% of players in their position in similar leagues. The positional comparison groups are: 
• Forwards 
• Wingers and attacking midfielders 
• Midfielders 
• Fullbacks 
• Center-backs 
• Goalkeepers The league comparison groups are: 
• English Premier League, Bundesliga, Serie A, La Liga and Ligue 1 
• Tier 2 European leagues 
• North and South American leagues 
• Asian Football Confederation leagues 
• Top tier women’s leagues

Player traits

The bar graph shows how a player compares to other players in their position on each stat. A green bar graph indicates they are among the best in their position at that stat, while a red bar indicates they are among the worst. The bar graph represents the percentile rank of the player for each stat on a per 90 basis, in the currently selected competition. Players are compared only against their positional peers from the currently selected competition. Using percentile ranks allows us to remove the impact of extreme outliers, and express the player’s relative performance in that stat category. A percentile rank of 90% for example, means that the player outperformed 90% of the players in that league, in their position.

Season performance

Expected Points (xPts) reflect the number of points a team was expected to earn from a match, based on the quality of their chances measured by Expected Goals (xG).xPts for a match are calculated by simulating possible outcomes using the quality of shots, expressed as xG. The simulation awards points for wins, draws, or losses based on xG.The xPts are accumulated over the season to form the "xG table", also known as the "Justice table", which provides an alternative view of team performance beyond actual points earned.