For several decades, American dirtrackers all looked behind the same way: They would leave their left hand on the bar and tuck their head under their left armpit to check on who was back there.
Over time, all sorts of theories were produced, most of them having to do with improved aerodynamics from keeping your head down.
But people kept asking why they did it, and eventually a pattern developed:
Chris Carr: "I saw Scotty Parker ride that way"
...Scott Parker: "I learned it from Springer"
...then Springer admitted: "Mert Lawill showed me that"
...at which point Mert admitted "I got that from Bart Markel"
..eventually Black Bart said he learned it from Carroll Resweber, who said he learned it from another Texas Racer, who...when they finally tracked him down... revealed The Secret
"Hell, boy, I was blind in my left eye...that was the only way I could see behind me"