Pick-hit rate is the percentage of matchups in a given pool (Top 5, Top 10, etc.) where the batter actually hit a home run. The MLB baseline HR rate per plate appearance is roughly 3–4%.
Capture rate measures what fraction of all scored-slate home runs on a given day were batters ranked in our top N. If the official slate produced 20 HRs and the top 10 contained 3 of them, top-10 capture is 15%.
The backtest and older live rows are replay estimates unless backed by an official timestamped model snapshot. See the performance methodology for the migration rules.