A gerund is a present participle (-ing verb) used as a noun. If the ‑ing verb acts as an adjective, it is not a gerund but a participial adjective. Thus, the expression a winning hand is not a gerund. It is simply a present participle (winning) used as an adjective.
Winning the race became his obsession.
(Gerundive phrase serving as the grammatical subject.)
I like swimming.
(Gerund serving as the direct object of the verb like.)
He perfected his technique of swinging the golf club.
(Gerundive phrase serving as the object of the preposition of.)