Why Bowling Pins Fall Differently: Pin Action Explained

Why bowling pins fall differently

Two shots can hit the pocket at what looks like the same spot and still leave completely different results: one strike, one lone 10-pin. The reason is pin action. The ball touches only a few pins itself; the rest fall because pins hit other pins. How that chain reaction runs depends on where the ball enters the pins, at what angle and with how much energy. Once you understand it, your pin leaves start to tell you what happened.

Pin numbering

To read pin action you need the numbers. The 10 pins stand in four rows, numbered from front to back and from left to right as you look down the lane:

• Row 1 (front): 1-pin, the headpin
• Row 2: 2-pin (left) and 3-pin (right)
• Row 3: 4-pin, 5-pin (center) and 6-pin
• Row 4 (back): 7-pin (left corner), 8-pin, 9-pin and 10-pin (right corner)

The pins stand 12 inches (30.48 cm) apart, center to center. The pocket is the gap between the 1- and 3-pins for right-handed bowlers and between the 1- and 2-pins for left-handers. The examples below are described for a right-hander; for left-handers everything is mirrored.

The physics of pin action

A bowling ball may weigh up to 16 pounds (7.26 kg). Each pin weighs between 3 pounds 6 ounces and 3 pounds 10 ounces (about 1.53 to 1.64 kg). The ball is therefore several times heavier than a pin, but it still cannot knock down ten pins on its own.

In an ideal pocket strike, a right-hander's ball touches only four pins: the 1, 3, 5 and 9. The other six fall through pin action: the headpin takes out the 2, the 2 takes out the 4, the 4 takes out the 7; on the right side the 3 takes out the 6 and the 6 takes out the 10; the 5 takes out the 8. The ball starts the chain, the pins finish it.

Deflection and drive

Every time the ball hits a pin, it gives up energy and is pushed off its line. This is called deflection. The opposite quality – the ball keeping its line through the pins – is often called drive. If the ball deflects too much, it passes the 5-pin or hits it too weakly, and pins are left standing.

What helps the ball hold its line:

• Entry angle – a steeper angle into the pocket carries better. A USBC pin carry study found an entry angle of about 6 degrees to be ideal.
• Ball weight – in the same study, heavier balls generally gave a greater chance of a strike. Our guide explains how to choose the right ball weight for your game.
• Pocket location – the study identified board 17.5 as the ideal point of entry.

Messenger pins

A messenger is a pin that travels across the pin deck and knocks down other pins, completing a strike or breaking up a split. For example, a pin from the left side can slide across the deck and take out the 10-pin. Messengers look like luck, but they come from the same physics as every other pin: they depend on the angle and energy with which the ball enters the pocket.

Light and high hits

Where the ball meets the headpin decides the direction the pins take:

• Light hit: the ball catches the headpin thinly and hits the 3-pin further on the side. On a light hit, the 6-pin often goes into the right gutter and the ball leaves the deck to the right of the 9-pin.
• High hit: the ball hits too much of the headpin. The headpin drives into the 5-pin, the 6-pin can go straight back and miss the 10-pin on its left.

For more on hitting the right spot, read our guide to hitting the strike pocket consistently.

The 10-pin: flat or ringing

The single 10-pin is the most common leave for right-handers. It comes in two versions, and they mean different things:

• Flat 10: the 6-pin falls weakly into the gutter in front of the 10-pin without touching it. This usually points to a weak or light hit: too little angle, too much deflection, or a ball that skids too long and does not finish.
• Ringing 10: the 6-pin flies around the 10-pin and misses it. This looks more energetic and tends to come from a strong, higher entry, where the 3-pin clips the 6-pin and sends it past the 10.

So the same leave can call for opposite corrections. Watch what the 6-pin does before you change anything.

Reading your pin leaves

A single shot says little. The pattern over several frames tells you more:

• 10-pin again and again: check whether it is flat or ringing (see above).
• 5-pin standing: usually a light pocket hit – the ball did not have enough angle or energy left to carry the 5.
• Bucket (2-4-5-8): the ball often loses energy too early and is rolling out before it reaches the pins.

Adjusting to what you see

The basic rule for adjustments is to move in the direction of your miss while keeping the same target on the lane. If the ball hits light (misses to the right), move your feet to the right; if it hits high (misses to the left), move to the left. For bigger changes in angle, many coaches use the 2-and-1 rule: for every two boards you move your feet, move your target one board in the same direction.

Adjustments only work if the rest of your delivery repeats. That includes your slide: rental shoes can slide quite differently from pair to pair, and your release point moves with them. Your own bowling shoes give you a slide you know and can rely on. BOWLIO shoes are made of genuine leather, top and bottom, with a slide sole under both shoes – suitable for left- and right-handed bowlers.

Making pin action work for you

Pin action follows physics, not luck. The ball only starts the process; the pins finish it. Enter the pocket with a good angle and enough energy, read what the 6-pin and your leaves tell you, and adjust one thing at a time.