The Bowling Rule of 31

Oil patterns are frequent talking points on bowling blogs and forums. Most bowlers, regardless of skill level, know and understand the distinction between less oil and more oil on the lane and what bearing this has on their performance — depending on their bowling ball. 

The most common pattern and the default oil application that recreational bowlers tend to encounter is known as the house lane pattern.

This is where oil is applied more generously down the center of the bowling lane, whereas the stretch that lines the gutters is left considerably drier. This gives the bowling balls a little extra push to hook back on course and keep moving in a straight line should they deviate from their intended path.

Generally speaking, the house pattern is a long oil pattern in which oil is applied on the first 35 to 45 feet of the bowling lane’s entire 60-foot length

It’s done to assist beginners and intermediates in getting more strikes, as the dry 15-25 foot stretch at the end means the ball will usually begin the hook phase immediately before the pins. It also means the bowling ball will be more likely to angle inwards if it gets too close to the gutter.

Length is the operative factor here, as it ultimately dictates the exit point and thus where your ball will begin to hook. This will also massively vary depending on the weight, core, and absorbency of the coverstock of your ball.


What is The Bowling Rule Of 31?

The rule of 31 is a common topic in bowling books and among players of the game. It is a formula that can help you approximate what board your ball will be at by the exit point of the oil pattern.

For example, if you’re bowling over an oil pattern that spans across 45 feet of a 60-foot lane, you will subtract 31 from 45. This leaves you with the number 14. 

This number is the approximate board where your ball will be at the break point of the oil pattern (board refers to the 31 actual wooden boards that the lane is composed of). In this instance, you want the ball to be at the 14 board when it exits the oil pattern.

Conversely, if you are using an oil pattern that spans 35 feet, your ball will exit the pattern and land at the 4 board. This, however, is not the same as the breakpoint, which will be a few feet further down.

This figure is just a starting point to help you decide how to best approach the lane depending on the length of the oil patterns each time you play.

Considering the degree of hooking capacity you have, which depends on the length of the oil pattern, you can then adjust your spin and lane play accordingly.

What do The Pros Think?

The term ‘rule’ can be deceptive, however. It should by no means be treated as a mantra that will give you infallible results every time you play. 

Shannon O’Keefe, coach of Mckendree University and WPBA bowler, echoed this same point when she took to Instagram to propose the term “guide of 31” as an amendment. She suggested that this change of term would put to bed any potential misconceptions among novice bowlers. 

Is The Rule of 31 Reliable?

It’s been argued that the rule of 31 is mainly applicable at tournaments where a bowling lane is allocated to each player during warm-ups, making it easier to anticipate the pattern length and ball motion. 

However, this rule or guide is helpful when noting one key element — the shorter the pattern, the wider the curve of the ball path. For example, if you can ascertain that the bowling ball will depart the forward oil at, say, the 4 board, then you can anticipate a wider hook than if it were to exit at the 14 board.

The rule of 31 is more traditionally applicable to sports shots rather than bowling at conventional bowling centers. This is because it’s possible to ascertain, and thus predict, the ball motion and ball reaction on freshly oiled lanes. 

Whereas if you’re bowling on a house pattern, you have to factor in the varying lengths that are difficult to account for and the oil depletion caused by other plays.

Difficulties are liable to arise when applying this method to house patterns if you take into consideration the traditionally short pattern of oil on public lanes. 

House lanes typically apply oil in a triangular shape with a limited amount outside the 10 board at 15-20 feet and the 15 board at 30 feet. If you try to apply the rule of 31 when working to this style of application, your ball would generate a substantial amount of friction when the oil ends and it enters the skid phase, hooking too early. 

This is on top of the inconsistencies in oil levels as a result of repeated plays. In short, if you’re throwing across a house pattern, coming in on the far left or far right part of the lane is the safest pocket to play in.


  • An efficient way to determine the hook of your ball
  • Can secure you some serious results on the right oil application
  • Helps you find the best breakpoint
  • A great starting point, even if not wholly accurate


  • Doesn’t necessarily apply to house patterns
  • Not always reliable, even on consistent oil applications


The bowling rule of 31 is a helpful guideline if you’re trying to assess how your bowling ball will react to a freshly oiled surface. Much of the time, you’ll be impressed by your performance when working by the rule, but be mindful not to treat it as gospel — especially on house applications where the oil pattern length on the bowling lane is unreliable.