Usages of decisivo
El error decisivo fue sacrificar el alfil.
The decisive error was to sacrifice the bishop.
De haber recordado la apertura, él habría tenido una ventaja decisiva.
If he had remembered the opening, he would have had a decisive advantage.
Es una lástima que este peón no haya sido decisivo.
It is a pity that this pawn has not been decisive.
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