You may have heard that this year the New Hampshire Grand Prix is using a new scoring system.  In this new system, we are all ranked by our "Age Graded Score", and then points are given based on our ranking.

So what is Age Graded Scoring (AGS)?  

In a nutshell, your AGS is the percentage of the speed you ran compared to the world record holder for your age and gender.

But before we get to AGS, I would like to step back and consider a "graded score".  Which is a better performance; a 5:00 mile or a 40:00 10K?  We all like to talk about our finest performance, but how do we compare sprints to marathons?  

This is a problem which spans more than just road racing and for a century has been addressed in the case of decathlons and pentathlons.  In the original decathlon scoring tables, if you tied the world record in an event, you would score 1,000 points.  If you ran half the speed, or twice the time, of a world record, you scored 500 points.  If you threw half as far, or jumped half the height, you scored 500 points.  In fact, the decathlon scoring system has evolved since then, but the idea of this point system has a great simplicity and attraction.

Graded scoring is usually out of 100 points instead of the decathlon's 1000 points,  but it is the same idea.  You can calculate it as the percentage of the speed you are running compared to the world record for that event.  Since you and the world-record hold both ran the same distance, you can also write it as

Score = 100 pts x (world-record-time)/(your-time)

So which is better; a 5:00 mile or 40:00 10K?  The world record for the mile is 3:43, for the 10k it is 29:17.  So 5:00 is 

   3:43/5:00 = 225 sec/ 300 sec = 0.75 = 75% or 75pts.  

Where as for the 10k;  

   29:17/40:00 = 1757s/2400s = 0.73 = 73% = 73pts.  

They are very similar performances!  

By the way, did anybody notice that I mixed in men and women's results?  A man running a 5:00 mile is a similar performance to a woman running a 40:00 10k.

So now, what is "age-graded-scoring"?

The idea of age-grading is that a performance should be compared to the world record for your age.  So replace the "world-record-time" with "world-record-time-for-my-age".  

Except even that is not quite right.

In the Figure below are plotted, with blue dots, all the best times for the Women's Half Marathon for ages 5 to 93!  But there is a bit of a problem here.  Betty Jean McHugh ran faster at age 78 then she did at 77. Evy Palm (age 46) beat out Nicole Leveque (age 45).  And there are no times between Margaret Davis (age 88 year, 2 days) and Gladys Burrill (age 93 years, 109 days)!

So instead of using the raw age-best times, a smooth curve is passed through the lines, which is called the "Age Standard".  Age graded scores are calculated by comparison to the age standard, not really the world record.

As one final note, since world-records improve, the standard also changes and every five years a new set of tables and curves are published.  The green curve is the 2010 standard, whereas the red curve is the 2020 standard.  It looks to me as if the change has been primarily driven by the performance of Deidre Larkin (age 85!)

There are similar tables and graphs for men and women, ages 5 to 90's, and distance from 1500 meter to 200 miles, on both roads and tracks.  

We are a sport which revels in our numbers!