Obviously the thing that stands out is the leap that Kobayashi makes with his first win in 2001 - he doubles the previous record of 25 hot dogs by winning with a count of 50 hot dogs in 12 minutes. That is incredible. Imagine Tyson Gay running the 100 yard dash in something like 4.7 seconds at the upcoming olympics and that is the kind of advance we are talking about. (Yes, I did just compare competitive eaters to the "world's fastest man.") A lot of the credit for Kobayashi's success usually goes to his training and technique:
Kobayashi is also known for his trademark body wiggle, referred to by some as the "Kobayashi Shake", to force food down his esophagus and settle more compactly in his stomach. He eats the hot dogs by splitting the frankfurter in half, swallowing both parts at once, and then dipping the buns in water, Sprite, or 7-Up and stuffing it in his mouth. He calls this the Solomon method.
You can see the differences in style between Kobayashi and Chestnut in this video of 2007's competition:
It will be interesting to see who takes this years competition. The safe money is probably on Chestnut to repeat but I'm betting on Kobayashi to reclaim the title this year.
PS - This remains the greatest Kobayashi video of all time: