Hermann Tilke created eight of the 19 circuits on the 2013 Formula One calendar. The figure for circuits with a contract to host a race next year is 11 out of 21.
When we add in the tracks at which he's had a hand in minor or major changes, the number is even higher.
Some would say that's a good thing. His tracks are designed to promote overtaking and have exceptional safety features.
To others it makes depressing reading. Tilke's tracks have criticised for being "carbon copies of each other" by three-time world champion Sir Jackie Stewart, who also said they don't penalise mistakes enough.
Those concerns are echoed by many fans. Complains of blandness and lack of character are also common.
So what would these fans think if Tilke was approached to redesign some of the sport's most famous classic circuits?
And more importantly, what might he do to them?