"Он собирается + infinitive" is not the future, but the present tense-form. it means that this person (он) RIGHT NOW is plans, looks forward to, desires, intends, dreams, or going to win. However, the victory is yet to be won IN THE FUTURE. So you basically have someone's attitude at this very moment ( собирается ) to a yet future event (выиграть).
In this particular meaning, "to be going to + infinitive" ( intending, planning to do smth), the Russian verb "собираться" is used either in the present (imperfective form), or in the past (imperfective or perfective).
However, I can't think of too many examples of using this verb in the future in this particular meaning of intending/planning to do smth, except for:
- Когда ты соберешься приехать к нам в гости? = Когда ты приедешь к нам в гости?
( when are you going to come and visit with us? = When will you come for a visit? )
However, this verb "собираться/собраться" is polysemantic, i.e. it has several different meanings ( to gather, to assemble; to prepare, to set out etc.), and is quite often used in the Future Tense in these other meanings.