A. OPENING STRAIGHT
There is a hazard to overcome even before the race starts - the build-up, parade and regirthing prior to the off lasts 25 minutes, over double the time it takes for any other steeplechase.
With 40 starters, riders naturally want a good sight of the first fence and after the long build-up their nerves are stretched to breaking point, which means the stewards' pre-race warning to go steady is totally ignored.
It is far easier to be near the lead and settle back into your planned position among the huge group than it is to fight your way up through the no-hopers and there are plenty of those.
Although the first fence is wide enough to accommodate all 40 starters and is quite inviting, it is the pure speed that causes fallers. The year after Aldaniti and Bob Champion triumphed, they and nine others exited at the first fence.
The second looms up very quickly before some riders or horses have properly recovered from the charge to the first and they are still going too fast.
Land safely over the third and a rider can start to relax himself and his mount. Horses feel everything the rider is bodily transmitting from confidence to fear.
The communication lines are through the reins to the horse's mouth and on to the brain and via the rider's legs through the ribcage to its heart and onto the brain.
The third has no nickname, yet remains the jockey's bogey fence.
With a 6ft open ditch in front of it and standing 5ft 2ins high, the fence poses several problems including the fact neither horse nor rider may actually see it through sheer weight of numbers bunching towards the middle of the course.
The other pitfall is the size and length of leap needed after two lesser jumps.
Precision is the key as standing off a stride too soon leaves a horse vulnerable to being overstretched on landing.
Mis-timing the approach can see the horse actually land in the open ditch or clout the fence halfway up. Either way, it is goodbye to any dreams of glory for at least another year.
Fences four and five give everyone time to regroup the senses and get into the rhythm that will conserve vital energy, but there is no time for complacency as the next three fences pose three very different questions.
Richard Pitman is a BBC TV pundit and former top jockey.