LVL·UP drills are built on the constraint-led approach — a research-backed method of teaching skills by designing the practice environment rather than directly instructing technique. It comes from peer-reviewed sports-science work by Renshaw, Davids, Buszard, Reid and others, published in journals including the ITF Coaching & Sport Science Review.
Where a drill card cites a specific statistic, the number comes from one of the public sources listed below. This page tells you what those sources are, what we do (and don't) claim by citing them, and how to get in touch if you spot something we got wrong.
Every specific percentage or numerical claim in a drill card traces to one of these public sources:
If a drill card says "ATP norm 54%" or "Match Charting Project shot-by-shot data," that's an academic-style citation — like a textbook quoting a research paper. It is not, and should not be read as, an endorsement of LVL·UP by anyone we cite.
LVL·UP is not affiliated with the ATP, WTA, ITF, USTA, LTA, NCAA, the Match Charting Project, or any individual coach, analyst, or athlete whose published work we cite. We use their published findings the way any coaching textbook would.
We keep an internal file mapping every specific number in the drill library to the public URL it came from, with the date we last checked it. If you want to see the source list, email hello@lvluptennis.com and we'll share it.
Tour statistics change as players and seasons evolve — a number that was correct on the day we cited it may shift over the following months. Where you see a card that uses a qualitative phrase like "high conversion rate" instead of a specific number, that's deliberate: either we haven't yet verified a current figure to substitute, or the principle holds regardless of the exact percentage.
Most drill cards don't cite a specific number — they describe a constraint (a rule, a target zone, a scoring tweak) and what coaches typically see when they run it. These drills sit on the constraint-led approach itself, not on any specific tour statistic. The methodology doesn't need a percentage to be valid; the percentages are there to give context, not to justify the drill.
If you spot a statistic you believe is incorrect, or you represent an organisation or individual we've cited and want to comment on the attribution, please email hello@lvluptennis.com. We respond within seven days and will correct or remove the citation if warranted.
For data-processing details (sub-processors, AI feature, where your data is stored), see the Privacy Policy. The "AI Draft Milestone" feature is the only place LVL·UP sends user-entered content to a third-party AI provider (Anthropic), and only when you explicitly click the AI Draft button — see Section 4a of the Privacy Policy for the full data flow.