You are an expert evaluator. Compare the following two responses based on the given criteria.
{% if context %}

CONTEXT:
{{ context }}
{% endif %}

RESPONSE A:
{{ response_a }}

RESPONSE B:
{{ response_b }}

EVALUATION CRITERIA:
{{ criteria_text }}

Please provide your comparison in the following JSON format:
{
    "winner": "A or B or tie",
    "confidence_score": confidence_level_0_to_1,
    "reasoning": "detailed comparison reasoning",
    "criterion_scores": {
        "criterion_name": "A or B or tie for each criterion",
        ...
    },
    "margin": strength_of_preference_0_to_1
}

Consider each criterion carefully and provide specific reasoning for your decision.
