It's worth noting that the ATP World Tour's top-ranked American, No. 23 Steve Johnson, has augmented his famous grin with a rather robust mustache.

It's difficult to understand why exactly Johnson opted for the 'stache look. It's not yet time for the annual Movember campaign, and it instantly turns 26-years-young "Stevie" into a questionably 46-years-in fellow.

Observers' reactions have ranged from thinking he looks like the second coming of John Newcombe to a Scotland Yard detective. I find that he looks like my 50-year-old uncle who lives in Michigan, but regardless, it's a some kind of becoming look on Johnson.

His on-court results during this perhaps short-lived 'stache era most recently included a tough first-round loss to Grigor Dimitrov in the China Open in Beijing. Johnson fell 7-5, 6-7 (9), 6-4 to the Bulgarian, who most recently upset Rafael Nadal in straight sets to reach the semifinals.

If it's a physical semblance of good luck, Johnson shouldn't shave that facial hair just yet.

Follow Jon on Twitter @jonscott9.