What Is a Split?
A split is a spare leave where the headpin (pin 1) has been knocked down, but two or more remaining pins have a gap between them that makes the spare extremely difficult. The ball can't simply slide across to get them both — you need to hit one pin into another, or thread a very precise shot.
Splits are marked with a circle (or sometimes an "S") on the scoresheet. They're the most frustrating leave in bowling, but understanding them helps you prevent them — and occasionally convert them.
Common Split Types
Not all splits are created equal. Here are the ones you'll see most often, from most to least makeable:
Bucket (2-4-5-8 or 3-5-6-9): Four pins in a diamond shape. Not technically always a split (depends on the 1-pin), but often grouped with them. Quite makeable — aim for the front pin and let the cluster fall.
4-6 Split: The "goal posts lite." Two pins on opposite sides of the deck but closer than the 7-10. Conversion rate: ~5–10%.
6-7-10 or 4-7-10: Three-pin splits with pins on opposite sides. Very difficult. You need to hit one pin hard enough to slide across and take out the other side.
7-10 Split: The iconic "goal posts." The two corner pins with nothing in between. Professional conversion rate is under 1%. For most bowlers, just knock one down and move on.
4-6-7-10 (Big Four): Four corner pins. Essentially two 7-10 splits stacked. Nearly impossible. Enjoy the rare occasion when you convert it.
What Causes Splits?
Splits aren't random bad luck (usually). They're caused by specific ball entry problems:
- Light pocket hit: The ball catches the headpin too thinly, deflecting through the middle but not driving through the 5 pin. This leaves pins on both sides — classic split territory.
- High pocket hit: The ball hits too much of the headpin, driving the 5 pin straight back but leaving corner pins standing. Causes leaves like the 4-6 or 8-10.
- Brooklyn hit: Crossing over to the wrong side of the headpin (left side for right-handers). This can cause unusual splits on the opposite side from where you expect.
- Flat ball: A ball with no hook or action tends to deflect more on impact. It pushes pins sideways rather than driving through them, creating gaps.
- Speed issues: Too fast and the ball skids through pins without proper pin action. Too slow and the ball deflects too much on contact.
The Pin Diagram
Understanding splits is easier when you can picture the pin layout. Here's the standard triangle from the bowler's perspective:
When the 1-pin goes down but pins remain with gaps between them, you have a split. The wider the gap, the harder the conversion.
How to Convert Makeable Splits
For baby splits (3-10, 2-7) and similar close leaves:
- Aim to hit the front pin on the side closest to the other pin — For a 3-10, hit the 3 on its right side so it slides into the 10.
- Use a direct, firm throw — This isn't the time for finesse. A straight, confident shot gives you the best chance of getting the pin action you need.
- Speed matters — Slightly more speed helps the front pin carry into the back pin with enough force to knock it down.
For bigger splits (4-6, 7-10), the strategy shifts to damage control. Hit one pin cleanly and take the single pin count rather than going for the hero shot and missing everything.
How to Prevent Splits
Since most splits come from bad entry angle, prevention comes down to first-ball accuracy:
- Hit the pocket consistently — A ball entering the 1-3 pocket (for right-handers) at the right angle minimises splits. The 5 pin is the key — when the ball drives through the 5, corner pins fall via chain reaction.
- Maintain ball speed — Consistent speed means consistent deflection. Speed changes are a common source of unexpected splits.
- Watch for lane transition — As oil breaks down over a session, your ball may start hitting lighter or higher. Adjust before the splits start appearing.
- Track your splits — If you're leaving the same split repeatedly, it points to a specific issue. The 4-6 over and over? You're hitting high. Lots of 3-10s? You're hitting light. The data tells you what to fix.
Splits Are Information
The most useful way to think about splits isn't as bad luck — it's as feedback. Every split tells you something about your ball's entry angle, speed, and axis on that particular shot.
Tracking which splits you leave most often reveals patterns in your game that you'd never notice otherwise. If 80% of your splits are baby splits on the right side, that's a very specific first-ball accuracy issue you can address.