Spare Shooting: the 3-6-9 System & Single-Pin Conversions
Spares · 3-6-9 system · Updated 2026-07-10
League bowling is a spare-shooting contest with occasional strikes. Strong league bowlers convert 90%+ of single pins; casual bowlers hover around 70% and donate the difference - a dozen pins a game.
The 3-6-9 system makes spares mechanical: same target, same swing, feet move a fixed number of boards.
The system (right-handed; mirror it for lefties)
Keep your normal strike target at the arrows. Only your feet move, in fixed steps of boards, so every spare uses the swing you've grooved all night:
| Leave | Feet move | Target |
|---|---|---|
| 2 pin | 3 boards right | Strike target |
| 4 pin | 6 boards right | Strike target |
| 7 pin | 9 boards right | Strike target |
| 3 pin | 3 boards left | Strike target |
| 6 pin | 6 boards left | Strike target |
| 10 pin | 9 boards left | Strike target |
Moving your feet opposite the pin angles the same ball path across the lane. The geometry does the aiming; you just repeat your shot. Clusters follow the same idea - shoot the key pin (the one nearest you) of the cluster: the 2-4-5 plays like a 2, the 3-6-10 like a 3.
Splits: know what's makeable
- Makeable: baby splits (2-7, 3-10) and fit splits - play them like their key pin.
- Slide plays: 4-5, 5-6 - hit the nearer pin thin and slide it over.
- Prayers: 4-6, 7-10, and the Big Four (4-6-7-10). Even pros convert 7-10s under 1% - the win is leaving fewer of them, not converting more.
Find out which pin is costing you
Because the app scores pin by pin, it knows your conversion rate for every leave - the spare-by-leave heatmap. The Coaching Plan then ranks the leaks by pins you'd win back: "Your 10-pin: 75% over 84 attempts, strong bowlers are 90%+ - worth +6 to your average" - and prescribes the 3-6-9 move or spare-ball fix. On Apple Intelligence iPhones, the AI Coach's Take writes the whole diagnosis from your real games, on-device.
Your spare heatmap is waiting. Score pin by pin and the app shows exactly which leaves cost you games - and how to fix each one. Free on the App Store. Download Bowling Score Keeper & Tracker on the App Store.
Frequently asked questions
What is the 3-6-9 spare system?
A fixed-adjustment system: keep your strike target at the arrows and move only your feet - 3, 6, or 9 boards (toward the side opposite the pin) depending on which single pin you're shooting. Same swing every time; the geometry re-aims the shot.
Why do bowlers use a plastic ball for the 10 pin?
Plastic doesn't hook, so the ball holds its line through the dry outside boards next to the gutter. A straight shot at a corner pin has a far bigger margin of error than a hooking one.
What percentage of single-pin spares should I make?
Strong league bowlers convert 90%+ of single pins. At 75%, single pins alone are costing you roughly 5-8 pins of average - the cheapest pins you'll ever win back.
Is the 7-10 split really unmakeable?
Nearly - televised pro conversion is a fraction of one percent. It needs a pin bounced out of the pit or slid across the deck. Treat 7-10s and 4-6s as count shots: hit one pin flush and move on.