Latin for to the victor goes the spoils?

The correct Latin translation of "To the victor the spoils" is "Victori spolia."

Explanation:

'Victorem' is the accusative case of the 3rd declension noun 'victor'. Use of a noun in the accusative case, together with the pronoun 'ad ', means 'to' in the sense of travelling - eg 'Ambulavi ad victorem' means 'I walked to the victor'. The construction (ad + accusative noun) does NOT mean 'to' in the sense of giving. For that you need the dative case, with no preposition. The dative of 'victor' is 'victori'.

The Word 'spolias' does not, and never did exist. The ending '-as' is 1st declension accusative plural, but the Latin Word 'spolium' (booty) is 2nd declension neuter. The Word 'spolium' was usually used in the plural, and the plural of 'spolium', in both the nominative and accusative cases, is 'spolia'.

"To the victor, the spoils" is thus "victori spolia"