There is a lovely area in Virginia to the west of Washington, DC, where I have bicycled for many years.

It is bounded by the Bull Run Mountains that run more or less north south about 50 miles to the west of the city. It extends to the Blue Ridge Mountains that run parallel another 20 or 25 miles to the west. The northern border is the Potomac River that winds its way up to West Virginia and the southern border is the Rappahannock River about 50 miles away.

Some call it “horse country,” which indeed it is. Others think of it as the range of Mosby’s Raiders, a battalion of Confederate Cavalry formed on June 10, 1863 in Rectortown, Virginia by Colonel John S. Mosby, CSA.

Mosby’s Raiders or Rangers (both appear to be correct) engaged in behind-the-lines guerrilla warfare and terrorized the Union Army. His territory generally extended the distance a horse could ride in a day (25 miles) in all directions and he attracted volunteers by offering the opportunity to profit from captured booty.

Uniforms consisted of “something gray” so you begin to get the picture that Mosby’s Men (yet another name) did not overthink adherence to accepted rules of warfare. It is alleged that “something blue” might also have crept into various uniforms, which did little to increase popularity with their enemies.

Nor was their preference for pistols over the sabers used by the Union Cavalry a cause for increased respect. Pistols were cheating until later adopted by both sides.

Given recent events, it is perhaps less than surprising to learn that the name “Mosby Heritage Area” — an excellent description of the boundaries of my bicycling domain — was recently changed to the “Virginia Piedmont Heritage Area.” That decision was taken by a friend of mine who hosts an annual Fall lunch at his house, which also happens to have been Mosby’s headquarters.

But all of this is background; colorful, perhaps, but nonetheless, background.

More relevant are the trends today. The outermost suburbs of Washington are at the easternmost edge of the area.

The farms, on which tractors and pick-up trucks constitute “farm vehicles,” according to their license plates, now compete with Audi A-5 convertibles filling that role. Another sign of change is the increasing number of crew-cab pick-up trucks towing trailers filled with industrial-strength lawnmowers from place to place, since that work is now quite often contracted out rather than performed by farm owners.

This is both the geography and the sociology of the previously-unheard-of-and-certainly-scientifically-useless “Mosby Test.”

What is to be tested?

Well, the winner of the election, of course, and the Mosby Test is not alone.

The Benjamin Franklin Elementary School in Yorktown Heights, NY has held an election for 48 years among its K-5 students and has never been wrong. Well, until 2016, when the children, after much hard work and study, picked Hillary Clinton.

The Spirit Halloween retail chain counts mask sales to predict election outcomes and they even got 2016 right. Dress up as Joe Biden or Donald Trump; your choice, but Spirit Halloween is counting.

Then there is the Changsha monkey, who devotes most of his time to picking the winners of soccer games. In 2016, after some banana consumption, he held up a sign showing the Chinese characters for Donald Trump.

Alan Lichtman, a professor at American University, just up the street from me, predicts elections without using polls and has been accurate every time since 1984. To my mind, he cheats by using actual science and measurable prevailing trends.

Finally, there is the Monogram Cup test in East Hampton, NY in which the sale of logo-embossed, politically themed reusable plastic cups determines the winner. It fell short in 2016.

Enter the Mosby Test.

A bicycle rider of a certain age and fitness level might cover 25 to 50 miles on a weekend day. This is at a pace of 12 to 15 miles per hour, offering ample opportunity for observation and reflection, as the miles go by.

I have been a frequent rider in that area for almost 10 years, which happens to include five elections — three Presidential and two off-year.

I have observed the signs supporting one candidate or another, but not kept track of them or where they were located. There are villages where opposing neighbors seem to try to outdo each other.

There also appears to be a north/south running water line between the increasingly Democratic eastern part of the Virginia Piedmont Heritage Area and the still Republican western part.

Over the last 10 years and the five elections during that period, that waterline appears to have crept further and further west and the trend continues today. It even seems to be accelerating.

With luck and good weather there will be about a dozen more observations of the Mosby Test before the election and none of them will be recorded. They are feelings that exist only in my head.

Nonetheless, the Mosby Test suggests caution for the President.