No, this does not mean stealing your opponent’s points and making them your own. Words often have very different meanings in non-mainstream usage. Abductive reasoning is the method by which an explanation is derived for observations when there is only partial information available. It makes a ‘best shot’ conclusion, one that is not 100% certain but is only the likeliest of all possible explanations.
Martha comes home to find the back yard all dug up full of holes. She is livid, thinking it is the work of her son Josh’s pet dog Bruno. Josh points out that Bruno has never done anything like that before, and mentions that he saw some stray dogs roaming the neighborhood. He formulates an alternative explanation: that it is the strays that are responsible for the mess.
Some examples of reasoning include jury decisions and medical diagnoses. In either case, the juror and the doctor do not have every possible bit of information: in the case of a jury they have the testimony of the defendant, complainant and witnesses, as well as whatever evidence may have been found, which may be incomplete, and the analyses of experts who themselves may not have all the pieces.
A doctor must rely on the patient’s self-reported symptoms, which are distorted by the patient’s subjective experience and potential inability to articulate them fully or accurately, as well as observable physical symptoms that are quite likely shared by dozens of ailments. Both the doctor and the jury must construct a best guess at what the truth is.
Abduction is obviously not as clear-cut as other forms of reasoning. It also involves a bit of creativity and intuition, which are not necessarily shared experiences. As a result, it will be necessary to spend quite a bit more time convincing your opponent to accept your argument.