It means that the defense attorney lists the facts that each witness, prosecution and defense, can provide to support our theory of defense . An excellent, dramatic presentation by an attorney will not save a case lacking favorable facts. Calling the defendant as a witness is usually a big mistake. There are naturally exceptions to this rule. But a defendant usually comes to the witness stand with too much baggage.
Every juror knows the defendant is the most biased person in the courtroom.
The prosecution is not allowed to say so, but everyone knows it. Criminal defendants are generally not very bright. They can easily be tripped up or impeached by the prosecution. They also have a unique way of irritating a jury. Surprise is the greatest weapon of the accused.