John Reid, who will take the mount on Single Empire on Saturday, has ridden in 12 previous Derbies, winning on Dr Devious in 1992.
He said: "It's the trickiest track there is. Horses get unbalanced, get very tired, lean, hang, do all the things you hope they won't. And the Derby is very competitive, there is tension, and normally a lot of runners.
"From the jockey's point of view it's the hardest race to ride in that there is and the most difficult course to ride on. But a Derby winner is a horse who can handle everything, a complete racehorse."
From the stalls, the Derby runners face a dog-leg to the right before straightening for a climb to the top of the hill, a rise of 135 feet in five and a half furlongs. Reid said: "It's imperative to have a good start. If you leave the stalls even a neck behind, you can end up finishing 10th. You're tracking right-handed to the apex of the first turn, then immediately back left to get to the rail.
"And once you've got your position, you have to hold on to it. Not so much going right, but coming back left. Horses have kicked up on the outside by this time, and then they drop back on to the left-hand rail. To avoid getting chopped off you need that speed to be able to hold your place, and to go on a little if need be.
"And if you are on the outside, if you haven't got the pace to come across you can end up seven wide and never get any better. It's a crucial part of the race; you can go in running fourth or fifth and come out running eighth or ninth."
From the start of the left-handed sweep downhill into Tattenham Corner the course drops 50 feet in about two and a half furlongs, a gradient which is flattened by the television cameras. Reid said: "It is very steep. You want a well-balanced horse, and one with a bit of speed. People say horses don't act down the hill, but if they don't it is usually because they're not quite good enough, and you're having to push. And pushing a horse and downhill - the two don't go together. You probably won't be on the bridle at this stage, but if you're on the right horse he'll be travelling within himself, taking you, which is important."
This is the part of the course where scrimmaging has caused falls and unseatings. Reid explained: "Halfway down the hill you hit another critical part of the race as the horses who have been up front start to crack and to come back through the field. If you're on the inside, or even two or three off the fence, you can get them coming back into your path, and you can get swept from a good position to a very bad one.
"At this stage it's probably a good idea to be three or four off the fence so at least you can manoeuvre a bit. By the time you get to Tattenham Corner you can drop back in again, so you don't have to swing wide down into the straight."
Into the three and a half furlong straight and the course continues to fall until about 100 yards from the winning post, where there is a sharp uphill climb. To compound the difficulty there is a camber towards the infield which becomes quite marked close home.
Reid said: "When you hit the straight you really want to be in the first five or six if you can. It's not impossible to come from a long way back, but it's difficult. You're running downhill until after the furlong marker.
"You want to watch, too, that you don't get stuck on the rails. The camber makes horses inclined to lug down towards the rail and it can be difficult to get a run through.
"And in the last furlong you want to have a bit in reserve. Up that last climb they can fold up very quick. On Dr Devious I hit the front a furlong and a half out, and it seemed a bloody long way to the line. "Reuse content