Application Of Numbers - Goal Difference

Football League table

Introduction

This is a statistical investigation about what makes a football team successful.

Hypothesis

“The goal difference of each team is a good way of indicating the teams league positions”

The more goals a team scores the higher in the ladder they should be, the more a team concedes the lower in the ladder they should be.

There are many reasons supporting my hypothesis, the main reason is that for any team to win a game they have to score more goals than their opposition. Winning matches gains points for the ladder, the more points you have, the higher in the ladder the team will be. Although goal difference is probably a good way of indicating how well a team is doing in a league, we can not totally rely on it because sometimes exceptions do happen where teams have better goal differences but are below teams with a lower goal difference.

Goal difference is found by taking the total number of goals you have scored, both home and away, and subtracting from that the total number of goals conceded. So your goal difference could be positive or negative, poitive being good obviously. The reason goal difference is important is that if two teams have the same number of points, the team which is higher in the league is determined by the goal difference.

Plans of action

To try and support my hypothesis I will use secondary data in the forms of league tables taken from websites, newspapers and internet to see if a better goal difference does make a team do achieve a higher league position. For this particular investigation, I will look at just the premier division and if my hypothesis looks correct I could consider looking at a different division in a different country. The use of different graphs will help me test my hypothesis.

The collection of primary data is not needed in this case since the information is available from most media sources and the league has already finished. If in some cases the results from the league table was collected on a weekly basis then that would be classed as primary data.

Data

Premiership Division - End of season 2004-05

Position Team P W D L F A GD Pts

1

Chelsea

38

29

8

1

72

15

57

95

2 Arsenal

38 25 8 5 87 36 51 83

3 Manchester United

38 22 11 5 58 26 32 77

4 Everton

38 18 7 13 45 46 -1 61

5 Liverpool

38 17 7 14 52 41 11 58

6 Bolton Wanderers

38 16 10 12 49 44 5 58

7 Middlesbrough

38 14 13 11 53 46 7 55

8 Manchester City 38 13 13 12 47 39 8 52

9 Tottenham Hotspur

38 14 10 14 47 41 6 52

10 Aston Villa

38 12 11 15 45 52 -7 47

11 Charlton Athletic

38 12 10 16 42 58 -16 46

12 Birmingham City

38 11 12 15 40 46 -6 45

13 Fulham

38 12 8 18 52 60 -8 44

14 Newcastle United

38 10 14 14 47 57 -10 44

15 Blackburn Rovers

38 9 15 14 32 43 -11 42

16 Portsmouth

38 10 9 19 43 59 -16 39

17 West Bromwich Albion

38 6 16 16 36 61 -25 34

18 Crystal Palace

38 7 12 19 41 62 -21 33

19 Norwich City

38 7 12 19 42 77 -35 33

20 Southampton

38 6 14 18 45 66 -21 32

Position Team Pld W D L F A GD Pts

P = no. of games played

W = no. of games won

D = no. of games drawn

L = no. of games lost

F = number of goals the team have scored

A = number of goals opposition have scored against team

GD = Goal Difference

Pts = Points earned

Just looking at the table I can say that goal difference is a pretty good indicator though I can see some variation in mid table. I will now produce a graph so I could look at this more closely.

Looking at this scatter graph I can say that only a good prediction is possible when using goal difference to determine how well a team is doing in the league. The graph shows a strong relationship between goal difference and points earned.

To sum this graph up we could say that the better the goal difference for a team the higher they are in the table but anomalies have shown that goal difference is not always the case.

For example, Charlton Athletic has a goal difference of -16 whereas Birmingham city have a goal difference of -6 which is a lot better but Charlton is still one place above birmingham city.

As we can see everton has a goal difference of minus 1 but they still finished in 4th postion, this shows that using the goal difference to determine position