Still, that's not a really good reason for preferring one method of 'ranking' over another. So, time for some meaningless numbers.
I've got this spreadsheet thing that can randomly generate a set of results for international football matches - with the likelihood of a result based on FIFA ranks and the typical relationship between past international results and FIFA ranks (now, there's a long story). If you run a lot of random trials (say, 50,000) for a group, and compare who would finish where based on GD and HTH rankings, you can get an idea of what the effects are.
So, I've done a number of different scenarios, based on a 4-team group playing a full 6 match schedule. To make it look vaguely realistic, the groups are of 4 African sides, using May 2007 FIFA ranks.
In each case, I've put in a table showing:
- Team
- FIFA rank
- % times finishing 1st under each method
- % times finishing 1st or 2nd under each method
Which gives a handle on what we might actually care about as a result of the group.
TRIAL ONE - A mixed group - no hopeless teams, but a range of abilities.
| Team | Rank | Ave Pts | Ave Pos GD | Ave Pos HTH | %1st GD | %1st HTH | %1-2 GD | %1-2 HTH |
|---|---|---|---|---|---|---|---|---|
| Cameroon | 968 | 13.1 | 1.34 | 1.36 | 73.7% | 72.6% | 93.1% | 92.7% |
| Guinea | 593 | 9.3 | 2.28 | 2.29 | 17.2% | 17.8% | 62.8% | 62.4% |
| Togo | 466 | 7.6 | 2.72 | 2.72 | 8.2% | 8.6% | 36.9% | 37.2% |
| Liberia | 224 | 4.0 | 3.65 | 3.63 | 0.9% | 1.0% | 7.2% | 7.7% |
TRIAL TWO - One good team - three no hopers.
| Team | Rank | Ave Pts | Ave Pos GD | Ave Pos HTH | %1st GD | %1st HTH | %1-2 GD | %1-2 HTH |
|---|---|---|---|---|---|---|---|---|
| Cameroon | 968 | 16.8 | 1.01 | 1.01 | 98.9% | 98.7% | 99.9% | 99.9% |
| Guinea-Bissau | 18 | 7.5 | 2.58 | 2.59 | 0.8% | 0.9% | 56.6% | 56.0% |
| São Tomé e Príncipe | 0 | 5.1 | 3.21 | 3.20 | 0.1% | 0.2% | 21.8% | 22.2% |
| Djibouti | 0 | 5.1 | 3.20 | 3.20 | 0.2% | 0.2% | 21.6% | 21.9% |
TRIAL THREE - Three evenly ranked sides - one no-hoper
| Team | Rank | Ave Pts | Ave Pos GD | Ave Pos HTH | %1st GD | %1st HTH | %1-2 GD | %1-2 HTH |
|---|---|---|---|---|---|---|---|---|
| Egypt | 694 | 11.0 | 2.00 | 2.01 | 33.8% | 33.8% | 66.7% | 66.8% |
| Senegal | 692 | 11.0 | 2.00 | 2.00 | 33.7% | 33.7% | 67.0% | 66.8% |
| Mali | 685 | 10.9 | 2.03 | 2.03 | 32.4% | 32.5% | 66.0% | 66.0% |
| Somalia | 13 | 1.5 | 3.97 | 3.96 | 0.0% | 0.0% | 0.3% | 0.4% |
TRIAL FOUR - One top side - three others around the same
| Team | Rank | Ave Pts | Ave Pos GD | Ave Pos HTH | %1st GD | %1st HTH | %1-2 GD | %1-2 HTH |
|---|---|---|---|---|---|---|---|---|
| Cameroon | 968 | 10.8 | 1.76 | 1.77 | 53.1% | 52.3% | 78.5% | 77.9% |
| Egypt | 694 | 7.7 | 2.72 | 2.72 | 16.2% | 16.5% | 41.3% | 41.5% |
| Senegal | 692 | 7.6 | 2.75 | 2.74 | 15.6% | 15.9% | 40.6% | 40.9% |
| Mali | 685 | 7.5 | 2.77 | 2.76 | 15.1% | 15.3% | 39.7% | 39.8% |
TRIAL FIVE - Two good - two bad
| Team | Rank | Ave Pts | Ave Pos GD | Ave Pos HTH | %1st GD | %1st HTH | %1-2 GD | %1-2 HTH |
|---|---|---|---|---|---|---|---|---|
| Cameroon | 968 | 14.2 | 1.42 | 1.42 | 59.2% | 59.0% | 99.3% | 99.1% |
| Côte d'Ivoire | 850 | 13.4 | 1.61 | 1.61 | 40.7% | 40.9% | 98.8% | 98.5% |
| Guinea-Bissau | 18 | 3.7 | 3.46 | 3.46 | 0.1% | 0.1% | 1.1% | 1.3% |
| Somalia | 13 | 3.4 | 3.52 | 3.52 | 0.0% | 0.1% | 0.8% | 1.0% |
TRIAL SIX - One good - two middling - one poor
| Team | Rank | Ave Pts | Ave Pos GD | Ave Pos HTH | %1st GD | %1st HTH | %1-2 GD | %1-2 HTH |
|---|---|---|---|---|---|---|---|---|
| Cameroon | 968 | 14.1 | 1.26 | 1.27 | 79.0% | 77.9% | 95.2% | 94.9% |
| Togo | 466 | 9.3 | 2.40 | 2.39 | 10.5% | 11.1% | 52.4% | 52.5% |
| Zambia | 462 | 9.3 | 2.41 | 2.40 | 10.5% | 11.0% | 51.8% | 51.9% |
| Somalia | 13 | 1.8 | 3.94 | 3.93 | 0.1% | 0.1% | 0.7% | 0.8% |
Pretty much overall, GD gives an advantage to higher ranked sides. Except where ranks are very close (so randomness comes into play), the GD ranking is more likely to see the best ranked side finish higher - or the best two sides finish 1-2.
Of course, there's millions of things that make this unrealistic, but the hope is (I suppose) that by looking at an average of 50,000 trials these are sort of smoothed away. However, I think the results are clear, and match what I might have expected, and match what happens in reality - namely that lower ranked teams tend to get an advantage from using HTH as the tie-breaker.
So, if you prefer the 'best' teams to make the finals, you're probably going to want GD used to rank, if you prefer 'surprises' (Angola ahead of Nigeria for example) then HTH is more your thing.
