"Oh, and Scott, get Mark to play me. He's the most talented one anyway"

This quote by Mark McKinney is most likely describing a musical efficiency. He is asking Scott to get Mark to bet him, indicating that Mark is the most gifted musician of the group. This could be because Mark has the most experience playing music, or since he has the most natural talent. It might also be due to the fact that Mark is the most passionate about music, and for that reason puts one of the most effort into his performances. Whatever the reason, Mark McKinney clearly believes that Mark is the very best choice for the performance. This might be a sign of Mark's confidence in his own abilities, or it could be a sign of his regard for Mark's musical talent. In any case, it is clear that Mark McKinney has a great deal of faith in Mark's musical capabilities.