From the rule book:
8.2.1: Turns. In aerobatic competition, a turn is divided into three parts:
1: Establishing the bank using a roll on heading.
2: The turn itself.
3: A roll back to straight and level flight on heading.
Let’s look at the turn during each of these three parts. First, the roll to establish the bank. This must be a roll of between 60 and 90 degrees; it must be performed on the entry heading; and the aircraft must maintain a constant horizontal line. Once the roll is completed and the angle of bank is established, the competitor immediately performs the turn. The turn must maintain the established angle of bank throughout. The aircraft must also maintain horizontal flight. The rate of turn is constant throughout and the maneuver must be wind corrected so that, for instance, a 360-degree turn will be a perfect circle. It should be noted that the wind correction cannot be performed by visibly changing the bank angle.
As soon as the aircraft is on the exit heading, the competitor performs another roll at a rate equal to the entry roll. Again, the aircraft must maintain a constant horizontal line.
Downgrades:
a: The angle of bank established by the initial rolling maneuver must be at least 60 degrees and not greater than 90 degrees. Any less or more is a 0.5 point deduction for every 5 degrees.
b: The angle of bank, once established, must remain constant. Any deviation is a 0.5 point deduction for every 5 degrees of deviation.
c: The rate of roll must be the same for the entry and exit rolls of this figure. Any deviation is a one (1) point deduction. SCA-22
d: The aircraft must maintain a constant altitude throughout the figure. Any variation would be 0.5 point deduction for every 5 degrees of change.
e: The rate of turn must remain constant. Any change would be not more than a one (1) point deduction for each change. Note that the rate of turn may appear to change in a strong wind, when it really isn’t changing. The judges must always keep the wind in mind and give the pilot the benefit of the doubt if there is any question.
f: The aircraft must begin and end on the prescribed heading. Any deviation is a 0.5 point deduction for every 5 degrees of deviation.