At the end of another long day of plodding, as a familiar melancholy descends and I contemplate how monumentally slow I have become in my late middle age, there grows in me a longing for a happier place, a fantasy land where I’m not the slowest guy on the track, but a stud whose times are repeated aloud by awed bystanders scanning the race results. Sometimes I give in to this longing, and allow myself to spend a pleasant half hour lost in happy illusions. I’m not referring to everyday nostalgia and idle reminiscing about the days of my youth; I’m talking about hitting the Internet and bringing up the WAVA age-grading tables, where I am — I hope you won’t think me immodest to admit it — a much better runner than I ever was.

The World Association of Veteran Athletes (WAVA) is the world governing body for masters long distance running, racewalking, and track and field. For those not familiar with the concept of age-grading, the WAVA tables provide a statistics-based way to compare performances achieved by men and women of different ages across a range of events. The age-grading tables compile the actual or theoretical world’s best performances for every age from 8 to 100 years old. Using the tables, any performance can be expressed as a percentage of the world’s best performance for the athlete’s age group. In this way, the performance of a 50-year-old can be “converted” to its equivalent open performance by looking up the open performance that scores the same percentage of world best open time.

(Here’s a handy age-grading calculator that uses the newest WAVA tables.)

Let me give an example:

Legendary Canadian distance runner Ed Whitlock is the only man 70 years or older to run a marathon in under three hours. At age 80, he ran the Toronto Waterfront Marathon in 3:15:54. When age-graded, that time is converted to an open time of 2:02:58, which should look familiar. It’s essentially identical to Dennis Kimetto’s world best open time of 2:02:57.

Or take the example of John Trautmann, former Georgetown star who at age 46 has re-emerged this winter as a world-class masters runner. Competing at BU on February 14, 2015, Trautmann ran the mile in 4:12.33, breaking the world indoor mark for M45. When age-graded, Trautmann’s time converts to a 3:47.8 open time.

But even for those of us not setting world records, age-grading tables are a wonderful diversion. Rather than dwelling on how our absolute times are declining over the years, we can convert those times and pretend we are getting faster, or at least not losing ground. In my own case, I’m delighted to note that my age-graded times since turning 45 compare very favorably with my best open times. For example, as an open athlete I ran 4:16 for the mile. While I’m quite proud of that, it doesn’t come close to being national class, and wouldn’t even stand out as a particularly good high school time these days. But as I get older, my age-graded times are looking better and better. At 45, I ran a mile that age-graded to 4:09. At age 47, I had dropped that to 4:08. In the real world, I was slipping further back into the pack, but in statistical terms I was forging ahead. At age 56, I set an age-graded “PR” of 4:06.9.

What a beautiful thing, this statistical trick that allows us to run the clock in reverse! There’s only one tiny problem with age-grading. It’s a fantasy. A happy, happy fantasy, but a fantasy all the same.

The basis of the illusion is the assumption that 90% of the world’s best at different age groups represents the same performance level. But why should this be so? In the open ranks, the very best athletes in the world train and compete to win the ultimate prize of an Olympic or World Championship medal. The incentives to do so are immense, and the competition so fierce that a runner can be very, very good and still be a non-entity on the world stage. A 21-year-old who runs the mile in 4:00 won’t even qualify for the NCAA championships, even though that runner is performing at 92.75% in age-graded terms, a level that WAVA considers world-class. A 50-year old who performs at the same percentage of the age standard, is probably winning national championships.

In other words, 90% of the standard has a fundamentally different meaning when the standard is established from a much smaller pool of athletes, where the truly world-class have little incentive to continue competing. And that’s exactly what happens with older ages. Every so often, a former world-class athlete will record an age-group mark that is so much better than the previous mark that it will blow up the existing age-grading tables. That happened a few years ago when former Olympic sprinter Merlene Ottey ran the 100-meter dash in 11.34 seconds at the age of 46. According to the existing age-grading tables at the time, Ottey’s performance was the equivalent of an open time of 10.12, more than 0.3 faster than the open world record! The World Masters Association responded by declaring that Ottey’s time was “nonrepresentative,” which is another way of saying that either the original tables were flawed, or that Ottey, herself, did not represent 46-year-old women. We’re about to see the same thing happen with Bernard Lagat and the M40 records.

But I don’t really care. I still love age-grading, and why not? This morning I punched in my 800 time from last Sunday’s meet, and the age-grading tables told me that my pokey time was the equivalent of an open time of 1:55.63, six seconds faster than I ever ran as an open athlete. What’s not to love?