The XAUUSD journal metrics that actually change decisions are expectancy in R, win rate read together with average R rather than alone, MAE and MFE distributions for sizing stops and targets, R broken down by UTC session hour, trading costs as a share of gross profit, and drawdown measured in cumulative R rather than currency.
Win rate alone is close to meaningless on gold because it trades off directly against average win-to-loss ratio; a 40% win rate at 2.5R produces a far more durable business than an 80% win rate at 0.25R.
Every metric requires a minimum sample before it is more signal than noise — roughly 30 trades for expectancy, 50 per bucket for MAE/MFE, and 30 per hour for session-hour breakdowns — and a single large outlier trade can flip the conclusion of a small sample entirely.