4 Aug 2009

Debunking Liverpool FC myths: No 3 – Liverpool are more effective with Steven Gerrard in the team

Liverpool fans and the media never tire of perpetuating the idea that Liverpool are more effective when Steven Gerrard is in the team, but is this actually the truth? It’s time to get a definitive, factual answer on this issue.

In the last entry in the ‘Debunking LFC myths’ series, I categorically proved that Liverpool do not struggle without Gerrard in the team. I’ll use the figures compiled in that article as a comparison to the new figures I reveal in this article.

So what is the answer? Do Liverpool achieve better results with Gerrard in the team?

The answer is NO.

To illustrate this, I've examined every competitive game Gerrard has played since the 2000-2001 season. Here are the results:

Total games played with Gerrard since 2000 – 448 (All competitions)

Wins - 244
Draws - 113
Defeats - 91

Goals For – 759
Goals Against – 397

Analysis

* Won 54% of games
* Lost 21%
* Drawn 25%

* Average goals scored per game – 1.7
* Average goals conceded per game – 1.2
* Unbeaten in 79% of games
* Failure to win in 45% of games

At first glance, these results look pretty good, but if we compare them to the figures for when Gerrard is NOT in the team, they become less impressive:

Total games played without Gerrard since 2000 - 80 (All competitions)

Wins - 48
Draws - 13
Defeats - 19

Goals For – 138
Goals Against – 72

Analysis

* Won 60% of games
* Lost 24%
* Drawn 16%

* Average goals scored per game - 1.7
* Average goals conceded per game - 0.8

* Unbeaten in 76% of games
* Failure to win in 40% of games

As you can see from the comparison above, the following are the same with/without Gerrard:

* Overall unbeaten ratio - 8 out 10 games (Wins + Draws ÷ Total Games)
* Goals scored ratio – 1.7 per game

The following differences are interesting though, and add weight to the argument that Liverpool do better without Gerrard in the team.

* Games won with Gerrard: 54%
* Games won without Gerrard: 60%

* Draws with Gerrard: 25% of games
* Draws without Gerrard: 16% of games

* Failure to win ratio with Gerrard: 45% (Draws + Defeats ÷ Total Games)
* Failure to win ratio without Gerrard: 40%

*Goals conceded with Gerrard: 1.2 per game
*Goals conceded without Gerrard: 0.8 per game

* Statistics courtesy of LFChistory.net

The bottom line is Liverpool win more, draw less and concede less when Gerrard is NOT in the team.

With these figures in mind, I would argue that it is now possible to accurately state that:

1. Liverpool achieve better results when Gerrard is NOT in the team
2. Liverpool DO NOT struggle without Gerrard in the team

Am I wrong?


NB. This is not an attack on Gerrard. These facts are open to interpretation and analysis and the point of this exercise is merely to debunk a myth, not suggest that Liverpool are better off without Gerrard.



7 comments:

  1. have you given up on the analysis of gerrard since rafa joined?

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  2. Hey Brando - no, I haven't given up.  I'll hopefully have it up this afternoon.

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  3. <span>You dont seem to understand statistics. Dont paraphrase without actually understanding what it means please.</span>

    <span>"In statistics...a statistically significant difference" simply means there is statistical evidence that there is a difference; it does not mean the difference is necessarily large, important, or significant in the common meaning of the word."</span>


    <span>Anyway...  
    For something to be proven by statistics, the numbers need to be large enough else most of the time, it cant be proven to be statistically significant. Its not to say though that large numbers are definitely needed. But it certainly helps.  
    Also, the difference in the 2 results compared is quite important. A big difference generally is more likely to be statistically significant. BUT again, a small difference may still be statistically significant, but generally its harder to prove, meaning you need bigger sample sizes.  
    </span>

    That's why this says:
    <span> simply means there is statistical evidence that there is a difference; it does not mean the difference is necessarily large, important, or significant in the common meaning of the word."</span>
    BUT, a large difference generally is more likely to be significant. U understand this?

    <span>In reply to that, yes, the difference in the two results does make a big difference (pun not intended). Generally speaking, the larger the difference, the higher the chance of statistical significance.... all else being equal...</span>

    Thats why i said the above. Notice that the difference may not be necessarily large true because small differences can still be statistically significant. BUT large differences are more likely and easier to be proven to be statistically significant. That's all i'm saying.

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  4. do you post this? I cant seem to find it.

    cheers

    ReplyDelete
  5. I haven't posted it yet. Will do soon.
    Sent using BlackBerry� from Orange

    ReplyDelete
  6. I think you need to weight the data so the number of games in both 'groups' can be considered equal enough otherwise, statistically the comparison is unreliable. 

    If you want to look for statistical significance, do also consider the 'effect size'.

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  7. Yes, you're very clearly wrong. This is a very silly article indeed. 

    Look at the kind of games he missed. Gerrard has featured in most games, so the sample size is lower for the games he's missed, as is the quality of opposition. A lot of those games being earlier rounds of cup competitions.

    Our best player would come in for the tougher, later rounds, and played most league games.

    ReplyDelete