It takes years to become a sushi master, it's not just something you can pick up, and great sushi is as much about how the sushi master handles the ingredients, as the quality of the ingredients themselves.
Here's a video that proves the point. In it, nigiri made by both a novice and a sushi master are compared, somewhat unconventionally, by placing them in a wind tunnel and under an MRI scanner.
The tests reveal just how well the sushi master's nigiri is made, particularly how delicately he handles the rice, so as to get the best possible flavour out of it.
Okay so unless you're eating your sushi in a gale, perhaps you don't care too much about the first test, but it's fascinating to understand more about the sushi master's craft. The clip is taken from a mid-noughties programme called Begin Japanology.