You can tell when an orienteer starts to get serious about improving - they start taking splits.
Instead of finding your average speed for the entire course, you use splits to find your average speed for every leg. This enables you to evaluate your performance for each leg and helps identify problems and areas for improvement. It's also fun to compare your splits with other runners.
It doesn't require e-punching equipment and computers to do this - we have been doing it for years with nothing more that a Timex watch. The watch has to be capable of saving enough splits (or laps) to cover an entire course. 8 is not enough, 50 or 100 is much better. The Timex Ironman with 100 lap memory works well. There are Casio models as well.
Punch Punch - It will never work if you can't remember to take the split at each control. Graeme Wilson, formerly of VOC, taught me to think "punch punch" - punch your control card, punch your watch. It has now become so automatic that I do it without thinking.
After you finish, measure the distance for each control. You can do the math and reveal everything in gory detail - I have an excel spreadsheet that does graphs, averages, histograms, etc. Or you can just eyeball it.
For instance if you are shooting for a 10 min/km average, that's 1 minute for each 100 meters, so a 650 meter leg should take you 6 1/2 minutes. If you are trying for 15 min/km, each 100 meters take 1 1/2 minutes, etc.
Of course this prevents you from lying about your performance - "I spent 20 minutes looking for that control" - the splits don't lie...