In the real world, when we want to compare how we think two people will compete in a match, we use weight classes. For example, here are the weight classes for boxing at the 2004 Summer Olympics:
| Weight Class Name | Max Wt | % Increase |
|---|---|---|
| Light Flyweight | 48 kg | - |
| Flyweight | 51 kg | +6.2% |
| Bantamweight | 54 kg | +5.9% |
| Featherweight | 57 kg | +5.6% |
| Lightweight | 60 kg | +5.3% |
| Light Welterweight | 64 kg | +6.7% |
| Welterweight | 69 kg | +7.8% |
| Middleweight | 75 kg | +8.7% |
| Light Heavyweight | 81 kg | +8.0% |
| Heavyweight | 91 kg | +12.3% |
| Super Heavyweight | 91+ kg | - |
The more traditional Weight Classes of the early 20th Century were:
| Weight Class Name | Max Wt | % Increase |
|---|---|---|
| Flyweight | 50.8kg | - |
| Bantamweight | 53.5kg | +5.3% |
| Featherweight | 57.2kg | +6.9% |
| Lightweight | 61.2kg | +7.0% |
| Welterweight | 66.7kg | +8.9% |
| Middleweight | 72.6kg | +8.9% |
| Light Heavyweight | 79.4kg | +9.3% |
| Heavyweight | Unlimited | - |
The steps change, but they average +7.37% per ranking for the Olympic scale, and +7.71% on the traditional scale.
I prefer a logarithmic scale and even numbers. A change of +7.98% per scale means (+30 ranks = x10 value) or (+9 ranks = x2 value). If we set (Rank 0 = 10kg), that gives us:
| Weight Class Name | Max Wt | Rank |
|---|---|---|
| Flyweight | 50.1kg | 21 |
| Bantamweight | 54.1kg | 22 |
| Featherweight | 58.4kg | 23 |
| Lightweight | 63.1kg | 24 |
| Welterweight | 68.1kg | 25 |
| Middleweight | 73.6kg | 26 |
| Light Heavyweight | 79.4kg | 27 |
| Heavyweight | Unlimited | - |