Ten Year Age Groups in NZ Orienteering

An Investigation into Events with around 200 Competitors

Michael Wood
1 Feb 04

Background

The NZOF Rules contain recommended course/class combinations (Appendix 4). For events up to 200 people these recommend 10-year veteran age classes. Most NZ events including Area Championships are around this size, and yet almost all run 5-year age classes.

The major reason behind the 10-year recommendation is better competition. Reasons advanced for 5-year age classes are (a) following IOF and (b) disadvantage to older competitors if wider age classes were used. This study examines these factors, using data from the area championships of Spring, 2003, and the Southern 6-day series of Jan 2004.

The numbers in each age class are presented. The need to follow IOF age classes is discussed. Data are presented showing the effect of combining 21A with 35A, 40A with 45A, 50A with 55A, and 60A with 65A. 21A is A-Long, not to be confused with Elite. A-Short and B classes are already broad-banded.

Numbers

The area champs of Spring 2003 had the following total published entrants, including DNFs and DNSs: Further analysis relies on times so we now focus on finishers.

2003 Area Champs Finishers in classes 21A to 80A
Class Auck Ch CD Ch Wgtn Ch SI Ch Tot Av
M21A 2 3 3 1 9 2.3
M35A 2 3 3 2 10 2.5
M40A 4 9 7 3 23 5.8
M45A 3 7 5 0 15 3.8
M50A 10 15 14 8 47 11.8
M55A 6 10 3 4 23 5.8
M60A 6 4 4 1 15 3.8
M65A 5 4 6 0 15 3.8
M70A 1 2 0 0 3 0.8
M75A 0 1 0 0 1 0.3
M80A 1 1 0 0 2 0.5
W21A 2 4 1 0 7 1.8
W35A 5 3 1 3 12 3.0
W40A 3 6 2 1 12 3.0
W45A 4 5 5 3 17 4.3
W50A 6 4 7 6 23 5.8
W55A 10 8 3 7 28 7.0
W60A 2 3 2 2 9 2.3
W65A 2 2 0 0 4 1.0

At this point we omit the 70+ classes. This is not meant to disparage those orienteers, who have contributed to orienteering over many years and provide superb role models for the lifelong nature of our sport. However the very small numbers in this age group will distort any analysis.

The overall average number of womens finishers per class 21-65 was 3.5, the average mens finishers was 4.9. The overall average was 4.2.

An interpretation of this is that provided you finish, you are more likely than not to be a placegetter (1st, 2nd or 3rd out of 4.2 finishers). Out of 64 class results, all finishers were placegetters in 33, or about half of them. One can question whether this represents a credible level of competition for a real sport.

IOF Classes

International events are governed by IOF rules.

For national and lower events, IOF member countries can make their own rules. NZOF has done so and in some respects departed from the IOF rules. The classes for competition can therefore be chosen to suit the country. In particular, numbers in NZ events are very much lower than in European and Scandinavian countries, and this has led to the recommended "10-course combination" for events up to 200 people. This combination has 10-year age classes for veterans.

Is the Higher Age-Group Disadvantaged?

It is self-evident that physical ability reduces with age. In a small population of a few hundred orienteers this effect may be masked by other factors.

Because adjacent 5-year classes often share the same course, it is possible to investigate the extent to which the winner of the higher age class is beaten by the winner of the lower age class. (Where an older person is known to have been running in the younger class, their performance is counted in the older class.)

2003 Area Champs: Class of the faster winner on the same course
Class Auck CD Wgtn SI Overall
M21/35 21 21 35 35  
M40/45 40 45 40 no 45's  
M50/55 Diff courses 55 Diff courses 55  
M60/65 60 60 Diff courses No 65's  
W21/35 21 21 21 No 21's  
W40/45 45 (actually 55!) 45 45 40  
W50/55 50 55 55 55  
W60/65 60 60 No 65's No 65's  
Younger beats older 6 4 2 1 13
Comparable cases 7 8 5 4 24

It would be expected that the younger age class would regularly beat the older, but this happens only slightly more than 50% of the time, 13 cases out of 24. The older age class beats the younger nearly as much. There is no evidence in these figures to say that the age classes 35, 45, or 55 would be disadvantaged competing with the age group below.

There are no cases of 65's beating 60's, and no conclusion can be drawn on this age group. But if the 65's are excluded from the totals, the younger classes beat the older slightly less than 50% of the time.

Aren't there Enough 50's and 55's for Separate Classes?

If there is one group that might have the numbers to justify separate classes at events under 200, it is 50 and 55. M and W 50/55 would be the only classes to average double-figure finishing numbers when combined; they would have yielded 13-18 finishers. We have used these classes to examine the median times and finishing order, in case the conclusions above are unduly influenced by the orienteers at the top.

Auckland Champs M50 and M55 were on different courses. (An M55 running M50 was 2nd.)
Auckland Champs Median W50 3-02-47, W55 2-37-21 (sum of two days). Finish order: 50,55,55,55,55,55,55,50,55,50,55,50,55,50,50,55
CD Champs Median M50 57-01, M55 58-57. Finish order: 55,55,55,55,50,50,50,50,50,50,50,55,55,50,50,55,55,50,55,50,50,50,55,55,50
CD Champs Median W50 51-45, W55 60-56. Finish order: 55,50,55,55,55,50,50,50,55,55,55,55
Wgtn Champs M50 and M55 were on different courses
Wgtn Champs W50 and W55 were on different courses. (A W55 running W50 was 1st.)
SI Champs Median M50 101-44, M55 83-25. Finish order: 55,50,60,55,50,55,50,50,55,50,50,50

There is no apparent pattern showing the 50's predominating near the top (or the other way for that matter). Out of five cases where medians can be compared, the younger is faster in three, the older faster in two. One may question whether one of the three, by under a minute, is significantly different from a draw.

Are the Results Repeatable?

The above analysis was repeated for the Southern 6-Day Series in Jan 2004. Because the investigation is into New Zealand events with up to 200 people, and there were substantial overseas competitors particularly veteran, the latter have been ignored. Day 3 was ignored as it was a score event.

On this basis the number of entrants was:

We first present the (NZ) finisher numbers.

2004 Southern 6-Day Finishers in classes 21A to 80A
Class Naseby Day 1 Naseby Day 2 Cuttance Waikaia Overton Tot Av
M21A 3 2 0 2 2 9 1.8
M35A 3 4 3 4 5 19 3.8
M40A 5 3 5 3 1 17 3.4
M45A 7 8 4 7 6 32 6.4
M50A 5 7 7 5 7 31 6.2
M55A 16 14 7 14 13 64 12.8
M60A 6 6 3 6 6 27 5.4
M65A 3 3 3 3 3 15 3.0
M70A 1 2 2 0 2 7 1.4
M75A 1 1 0 0 0 2 0.4
M80A 1 1 1 0 1 4 0.8
W21A 6 5 5 5 5 26 5.2
W35A 4 3 2 4 3 16 3.2
W40A 5 6 3 5 3 22 4.4
W45A 8 10 3 8 4 33 6.6
W50A 5 4 5 7 5 26 5.2
W55A 14 13 10 12 6 55 11.0
W60A 7 7 5 6 8 33 6.6
W65A 3 3 2 1 2 11 2.2
W70A 2 2 2 2 2 10 2.0

As before we omit the 70+ classes. The overall average number of womens finishers 21-65 was 5.6, the average mens finishers was 5.4. The overall average was 5.5.

Again you were more likely than not to be a placegetter (1st, 2nd or 3rd out of 5.5 finishers). Out of 80 class results, all finishers were placegetters in 26, or about one third of them. This is consistent with the Area Champs findings.

We now look at which age class the fastest times came from, where adjacent classes were in the same course.

2004 Southern 6-Day: Class of the faster winner on the same course
Class Naseby Day 1 Naseby Day 2 Cuttance Waikaia Overton Overall
M21/35 35 35 No 21 finishers 35 35  
M40/45 40 45 40 45 45  
M50/55 55 (actually 60!) 55 55 55 55  
M60/65 65 60 60 60 60  
W21/35 Diff courses Diff courses Diff courses Diff courses Diff courses  
W40/45 45 45 45 45 45  
W50/55 55 55 50 55 55  
W60/65 65 65 65 60 65  
Younger beats older 1 1 3 2 1 8
Comparable cases 7 7 6 7 7 34

Whereas the older and younger classes were about even in the Area Champs, here the older winners are more likely to be faster than the younger. This paradoxical result illustrates that factors other than the 5-year age difference are more significant.

Before, we couldn't draw conclusions about the 60/65 age group, but this time they show the same result as the others. There is no evidence in these figures to say that the age classes 35, 45, 55 or 65 would be disadvantaged competing with the age group below.

Finally, we examine the 50/55 results in detail. This time W40/45 is the only other class that would average double figures when combined, and then only just: M and W 50/55 when combined would have yielded 16-19 finishers.

Naseby Day 1 Median M50 94-56 M55 86-49. Finish order: 55,55,55,55,55,55,55,50,55,50,55,55,50,50,55,55,50,55,55,55,55
Naseby Day 1 Median W50 98-56 W55 89-24. Finish order: 55,55,55,55,55,55,50,50,55,50,55,55,50,55,50,55,55,55,50
Naseby Day 2 Median M50 80-26 M55 81-49. Finish order: 55,55,50,55,50,50,55,55,55,50,55,55,50,55,55,55,50,55,55,50,55
Naseby Day 2 Median W50 68-32 W55 84-56. Finish order: 55,50,50,50,55,55,55,55,55,55,55,55,55,55,50,55,55
Cuttance Median M50 81-04 M55 98-21. Finish order: 55,55,55,50,50,50,50,50,55,55,55,55,55,50
Cuttance Median W50 98-52 W55 129-00. Finish order: 50,55,50,50,55,50,55,55,55,55,55,55,55,50
Waikaia Median M50 94-31 M55 90-47. (NB course different although length within 100m) Finish order: 55,55,55,55,50,55,55,50,55,55,55,50,55,55,50,55,55,55,55
Waikaia Median W50 114-26 W55 101-32. Finish order: 55,55,50,55,50,55,55,55,55,55,55,50,50,50,55,50,55,55,50
Overton Median M50 64-40 M55 63-57. (NB course different although same length) Finish order: 55,55,55,50,55,50,55,55,55,50,55,50,50,55,55,55,55,55,55,50
Overton Median W50 75-28 W55 75-56. Finish order: 55,50,55,50,55,50,55,55,55,50,50

There is no apparent pattern showing the 50's predominating near the top (or the other way for that matter). Out of the 10 cases the younger is faster in five, the older faster in five. When two cases of difference under a minute are discarded, the result is four-four.

Conclusion

The four area championships in Spring 2003 were events of up to around 200 competitors. And, if the significant number of overseas competitors is ignored, so was the 2004 Southern 6-Day Series.

In classes 21A to 65 there was more chance of a finisher placing 1, 2 or 3 than not getting a placing. Combining 21A and 35, 40 and 45, 50 and 55, 60 and 65 would have doubled the average finishers per class to 8.4 (Area Champs) or 11.0 (NZers in Southern 6-Day).

There is no evidence that the age classes 35, 45, 55 or 65 would be disadvantaged competing with the age group below.

This has been investigated by comparing the winners of all classes which compete on the same courses. In the case of the largest groups 50 and 55, it has also been examined by comparing the median times, and by visual inspection of the order that would have resulted from combining the classes.

This is not necessarily to suggest that the Southern 6-Day should have used ten-year classes as the total entry was much larger than 200. Nor is it to deny the pride with which we celebrate the continuing participation of our oldest orienteers.

However all our major events should provide maximum opportunity for competitive orienteers in these age groups, as we acknowledge they should for elites and juniors from their mid-teens. This would be enhanced if the fields were stronger, which ten-year age classes in events up to 200 people would achieve.

This page written by Michael Wood, installed on 1 Feb 04.