Where Mully's advice comes from
Most golf AI lets you assume it made the advice up. Mully doesn't work that way. Every benchmark it cites traces to a named, published source, and here is the whole tree. If a number isn't backed by one of these, Mully doesn't use it.
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Primary authorities
Instrument makers, governing bodies, and published research. Every numeric fact and ball-flight law traces here.
Optimal launch angles, tour averages, optimizer standard assumptions. Spin-rate tour averages, optimizer spin, amateur Combine spin by level. Smash factor by club, tour averages, amateur Combine smash by level. Spin axis sign convention, near-straight window, curvature by yardage. Ball-flight laws: face angle = start direction, face-to-path = curvature.
Strokes-gained framework, putting make %, up-and-down %, long-game dominance of scoring.
Warm-up science: dynamic vs static stretching effects on power, and warm-up protocols shown to improve driver carry distance.
Peer-reviewed evidence that a dynamic warm-up significantly improves TPI physical screen composite scores in adult golfers (median 33 to 36).
Golf injury epidemiology (spine, elbow, wrist, shoulder) and warm-up's effect on injury risk; skipping warm-up ~3.2x injury odds.
RCT on acute effects of dynamic vs resistance-band warm-up on golf drive ball velocity and launch angle in skilled golfers.
RCT comparing dynamic warm-up, PAP, and swing warm-up on driving distance, clubhead/ball speed, smash factor, and accuracy in elite golfers (dynamic +2.65% distance).
Putting and ball-roll biomechanics: face angle/rotation, putter path, launch/skid/roll transition, and putter-fitting effects on roll.
Shot databases
Large shot-tracking datasets from named companies. The per-handicap benchmarks come from these.
Scratch and by-handicap GIR, proximity, fairways, driving distance, scoring. 3-putt rate by handicap vs PGA Tour and putting make% by distance (1-5 handicap averages a 9.44% three-putt rate).
Putting make % by distance and handicap, 3-putt rate, scrambling by handicap. Up-and-down success rate and proximity by club type (wedges vs 8i/9i/PW chip-and-run) for a 15-handicap golfer.
Driving distance and fairway accuracy by age/handicap, wayward-drive (penalty/recovery) rates, and 2018-2024 distance trends from Arccos's 6.5M-shot dataset (men avg 224.7 yds; 0-4.9 hcp ~250 yds).
Amateur strokes-gained benchmarking (driving, approach, short game, putting) from a 100,000+ amateur shot database (Mark Broadie-affiliated).
Live current-season PGA Tour strokes-gained leaders by category (Total, Off-the-Tee, Approach, Around-the-Green, Putting).
Instruction
PGA-credentialed coaching whose drill methodology and feel cues Mully can draw on. Vetted for credential, not social-media tips.
PGA pros Piers Ward + Andy Proudman. TPI-certified, launch-monitor-validated fault diagnosis and drill prescriptions. Tour-player collaborations (Russell Henley, Tommy Fleetwood).
Feel-based instruction with biomechanics grounding. Mnemonic teaching system (G.R.I.P.S., S.W.E.E.P.) for on-course recall. Best for simplifying technical fixes into one-cue feels.
Hogan's 1957 Five Lessons (grip, stance, backswing, downswing, integration). Sequential-fundamentals method — master each block before moving forward. Surfaced via Christo Garcia's Classic Golf Swing channel.
Mike Granato + Shaun Webb + Kevin Sprecher. 3D motion capture (GEARS), force plates, TrackMan analysis. Best for understanding the biomechanical 'why' behind a fault — debunks 10+ common swing myths with data.
A few of the actual yardsticks
Real reference figures Mully reads your numbers against — baselines, not targets it forces on you.
- Driver
PGA Tour avg: launch ~10.4 deg, spin ~2,545 rpm, smash ~1.49. Well-struck target smash ~1.50. Optimizer (~94 mph club speed, level attack): launch ~13.6 deg, spin ~2,772 rpm. Optimal launch/spin must be fit to the player's club speed and attack angle.
TrackMan - 6-iron
PGA Tour avg: launch ~14.0 deg, spin ~6,204 rpm, smash ~1.39.
TrackMan - Pitching wedge
Target smash ~1.25; optimizer spin ~8,408 rpm at ~72 mph club speed.
TrackMan - Where strokes are won
Strokes gained splits scoring into Off-the-Tee, Approach, Around-the-Green and Putting. The long game, especially approach play from ~150-200 yards, correlates most strongly with scoring; 'drive for show, putt for dough' is overstated. Added driver distance is worth roughly +0.75 strokes per extra 20 yards for a strong player.
Mark Broadie (Every Shot Counts) - Greens in regulation by handicap
GIR: scratch ~56% (~10 greens/round); 10-HCP ~34%; 18-HCP ~23% (~4 greens). Approach proximity: scratch ~26 ft on GIR approaches (~44 ft all approaches); 18-HCP ~35 ft.
Arccos - Fairways and driving distance by handicap
Fairways hit: scratch ~51%. Driving distance: 0-5 HCP ~243 yds, 10-HCP ~227 yds, 16-20 HCP ~209 yds.
Arccos