1) Liga scoring/conceding rate per game per team:I took the league table, the number of goals scored by all teams in 28 weeks is: 824 goal in 280 games. Deducting
Barcelona Games, Goals scored, and Goals conceded, Means that in 252 Games the other Liga teams scored 716 goals against each other, Making the average goals scored/conceded by a team per game is:
Liga Average Rate (
LAR) = 716 / (2x252) = 1.421 Goals/team/game.
2) Calculating Each Team conceding/scoring Average per game:In the initialized table (without
Barcelona goals) Dividing number of goals every team scored by the number of games played. For example:
Villarreal: Scored 44 goals in 27 games (deducting the goal scored against
Barcelona in their 28th game). So their Goal scoring Average (
GSA) = 44 / 27 = 1.63 Goals per game.
Villarreal Conceded 35 goals in 27 games (deducting the 2 goals conceded by
Barcelona in their 28th game). So their Goal Conceded Average (
GCA) = 35 / 27 = 1.296 Goals per game.
And the same goes for all the Liga teams to measure there average performance in order to benchmark it with their performance against
Barcelona, and
Barcelona performance against them.
3) Goals Value:A goal Scored against
Sevilla (
GCA = 0.852) for example, must have a higher value than a goal scored against
Almeria (
GCA = 1.5) or any other team with weaker defense than
Sevilla. The same for goals conceded. Its important to take in consideration the opponent Defense/offense strength before comparing
Barcelona performance against two different opponents.
To demonstrate that, I will take two games as an example:
21 Feb 09
FC Barcelona 1 - 2
Espanyol1 Mar 09
Atlético Madrid 4 - 3
FC BarcelonaEspanyol Scored two goals against Barcelona.
Atletico scored four. But that doesn’t mean
Barcelona Defense against
Espanyol was better.
Espanyol Scores 0.846 goals per game in the Liga.
Atletico scores 1.889 goals per game. So to evaluate the Values of numbers of goals conceded in the two games, we need to evaluate the value of the two results if the two teams had the same offense strength. The only way I found to do so, is to calculate the goals value based on a fixed common factor, and that is the LIGA Average Rate (
LAR).
The logic here is: If
Espanyol (0.846 goals/game) Scored two goals against
Barcelona defense in that game, Relatively, how many goals a team of 1.421 Goals/game (
LAR) would have scored back then?
0.846 -------- > 2 goals scored
1.421-------- > Goals Relative value = (1.421 X 2) / 0.846 = 3.359 Goals.
While
Atletico ( 1.889) scored four goals, so the Relative goals Value Based on (
LAR) is
1.889 -------- > 4 goals scored
1.421-------- > Goals Relative value = (1.421 X 4) / 1.889 = 3.01 Goals.
And it shows that Even though
Atletico scored two times more goals against
Barcelona than
Espanyol did, yet
Barcelona Defense was more fragile against
Espanyol.
So the general criteria to evaluate goals scored by any team against
Barcelona, takes the number of Goals netted and the opponent Goal scoring average (
GSA) is:
Opponent
GSA ------ > Number of Goals Scored
LAR------ > Goals relative value (Calculated).
The same goes for goals scored by Barcelona taking in consideration the opponent conceding average per game (GCA). Espanyol (GCA = 1.607) , Atletico (GCA = 1.308).
Opponent GCA ------ > Number of Goals scored by barcelona
LAR ------ > Goals relative value (Calculated).
Based on that, the goal scored by Barcelona against espanyol has the value of ( 0.884 ) while their three goals against Atletico has the Value of ( 3.259 ).
4) Offense efficiency by game: is an indicator that compares Barcelona offense efficiency against a certain team to the efficiency of the other teams against that team.
Taking Valencia as an example, their GCA is 1.334 Goals per game. This means that the other teams in the liga had the offense efficiency to score an average of 1.334 Goals per game against Valencia. Barcelona scored 4 goals against Valencia with a scoring value of 4.261. That makes Barcelona offense efficiency in this game exceeds the average Liga efficiency against Valencia by: 4.261 – 1.334 = 2.927
While against Getafe (GCA=1.519), Barcelona scored one goal with a relative value of 0.935. That makes Barcelona offense efficiency in this game inclined under the Liga offense efficiency against Getafe: 0.935 – 1.519 = - 0.584
5) Defense Fragility by game:
Governed by the same logic used to calculate Offense efficiency, the defense Fragility is an indicator that compares Barcelona defense performance to the over all defense performance of liga teams while playing against a specific team.
Taking Osasuna as an example, their Scoring average against La liga teams is (GSA = 0.963 goals per game), that’s the average number of goals Osasuna scores against La Liga teams. They scored two Goals against Barcelona with a relative value of 2.951.
That makes Barcelona defense fragility compared to la liga teams defense fragility average against Osasuna = 2.951 – 0.961 = 1.99.
Keeping in mind that, the Offense efficiency rate show the minimum efficiency value, taking in consideration the scoring opportunities missed and the fact that when Barcelona score a certain number of goals they automatically decrease their over all performance offensively.
In the other hand, the fragility rate indicates the minimum fragility level, taking in consideration the opponent offense failure to score clear opportunities, leading to less conceded goals for Barcelona, because of the Opponent mistakes, and not Barcelona Defense quality. (And again, when we say defense we are talking about the defense system, not the defenders). The only exceptions are the games where Barcelona ended with a clean sheet, that’s when the opposite is true. The defense was much better than needed to overcome opponent offense quality, so ended with clean sheet. It means that defensively we were better than the needs of the GSA of the opponent, but it's impossibly to know to what extend we were better.
Finally, to make a more accurate indicator, we need to measure the GCA, GSA, and LAR during the period of the evaluated game (a segment of 5 games before and 5 games later) rather than the overall rate of 28 games. This way you take the periodic form in consideration, rather than the gross form. And there is also a need to take the away/home impact in consideration. I am not sure how far all that will change the results, but knowing that it will need a huge work to achieve that level, I had to accept the level I based my analysis on, as a more accurate method than taking the rough goals numbers and base the analysis upon.
And it was encouraging because the charts and numbers met the observation methodology to evaluate the team performance.
Yet, any other criteria will be more than welcomed to be discussed on the table.