In a legal dispute, the defendant is initially presumed to be innocent, while the prosecution has the responsibility of producing evidence persuasive enough to establish any guilt. This evidence is known as the Burden of Proof.
In a debate, The Proposition has the Burden of Proof (rather than the opposition).

Opposition Approach to selecting arguments (P E T A L)

#Is the motion Practical?

The motion isn't Ethical,

The motion has been Tried before and failed

There are better Alternatives

The consequences of the motion have Logical inconsistencies

Reference: Seán Dolan http://ulsites.ul.ie/law/dr-seán-dolan-0