Novice runners frequently repeat the following misconception -- "the bulls will run to the inside of the turn," or "the bulls will run to the outside of the turn." This is folly. There are various turns (some dramatic; some listingly) in the Pamplona bull running course, and the reality is....the herd will run wherever it wants. Some mornings they are so fast they can't stay tight in the turn. Some mornings they take the turn like a professional racer. You cannot know.
The most significant turn is located at "la curva" where runners and the bulls turn right onto c/ Estafeta. Among many other dangerous parts of the course, this is a very dangerous corner.
Anyone that tells you to stay to one side or the other because one side is safer than the other is ill-informed. Again, these Spanish bulls have an athletic prowess than you cannot understand until you see them in action. If they want to take the corner tightly, they will. If they miss taking the corner tightly, they are able to come back and try again. The bulls follow no rules.
For example...here the herd takes the corner to the right.
Here the herd takes the corner right down the middle.
Here the herd takes the corner to the right, with our buddy Gus brilliantly taking the corner with them.
Here the herd take the corner on the left, all the way up against the wall.
Here the herd takes the corner on the right.
As the shepherds will tell you, they've NO IDEA where the bulls are going to run. There are so many factors that predictions are wothless. The safest plan -- run as fast as you can, and tuck into a corner on either side. One guarantee -- if you aren't running, you will get run over by bull or runner.