{
    "event": "Custom initial position (Black to play)",
    "initialPosition": "rnbqk2r/pppp1ppp/5n2/2b1p3/2B1P3/5N2/PPPP1PPP/RNBQ1RK1 b kq - 0 4",
    "mainVariation": [
        "O-O"
    ]
}