Carl's hard-to-train melee skill, sitting at nine and offered a +2 boost by the Revolutionary specialty.
The Revolutionary specialty offers +2 to Unarmed Combat along with faster melee training. Carl describes the skill as similar to powerful strike; it currently sits at nine and is very difficult to train up.
He reasons that getting it to 11 would likely give him an additional advantage, since it would push the skill past ten. He chooses Agent Provocateur anyway.
Carl's melee skill, left at nine when he passed on the Revolutionary branch.