Personal Best is the progress tracker that ties the whole site together. Every tool — the CPS tester, all four mode testers, the click counter and click battle — writes its sessions to one shared history, and this page turns that history into something you can learn from: your best CPS overall and per technique, a progress chart with a trend line, streaks, recent sessions, battle records and a searchable session list.
The reason it matters is that click speed training is a numbers game. Without a record, a plateau feels like a wall and a breakthrough feels random — with a trend line, both are visible as data. Because every session includes the technique metrics from the mode testers, you can correlate your alternation rate or interval consistency with your rising CPS, and see exactly which change moved the needle. And like everything else on the site, it's private: history lives in your browser's LocalStorage with no accounts and no server, and you can export everything to CSV or wipe it with one click at any time.