Selected by Matt Wragg - This is pretty much a masterclass in strobe placement - I'd guess there are at least three here - one on the rider, one on the takeoff and another picking out the line of the grass behind to create a lovely balance between the light and dark.
@thomaluettgen -It's def true! Sterling is hands-down one of the most successful (and impressive) bike photographers out there. No disrespect whatsoever . My joke might have missed a few people...
Matt Wragg- There are two on the rider resulting in the cross-lighting. Easiest way to see this is by looking at the hard kick on his thigh/knees and then the same hard kick on his face. These definitely come from opposite sides. Depending on the type of strobes, and modifiers on them, these two side lights could also provide the light that's hitting the grass, negating the need for a fourth light. Combine this with slight underexposing of your background to set off the subject, add in beautiful symmetry, a simplistic composition, a subject on a third (and of course a Brandon Semenuk) and you wind up with a great image.
This is why guys like Sterling Lorence get POD often.. It's hard for an amateur photographer to capture a shot like this; it's why they're professionals.
(sarcasm)