2012's series provisionally includes nine races with best five to count. All are multi-terrain to a greater or lesser extent and undulating or hilly. There is a good chance of two new summer races being added but neither have yet been confirmed as going ahead.
Performances are measured relative to the median time (middle finisher), then scaled according to age and gender via formulae approximating to the age-gradings from tables issued by WAVA (the World Association of Veteran Athletes):
your_score = median_time / your_time * 100% * age-factor
The middle finisher gets 100% raw (ungraded) points and the winner about 140%. After scaling vets have more points and seniors the same. This may seem a bit complicated but positions obviously aren't comparable between races with different numbers of runners, and percentage of winning time is very sensitive to which particular speed merchants happen to turn up.
Team scores are computed from the average (mean) percentage age-graded positions so is a measure of the performance of the entire team rather than just the first few. It's not perfect but then nor's the age-grading! At least five runners are required for a team to score.