Rules and regulations

The regulations listed here are generally based around regulations set by the United States Bowling Congress and the British Tenpin Bowling Association. These rules are followed by all sanctioned leagues and events, such as tournaments.

This information is clarified by the World Tenpin Bowling Association in its “Statutes & Playing Rules”.

Playing area

The sport of ten-pin bowling is performed on a straight, narrow surface known as a lane. This bowling lane is 60 feet (18.29 m) from the foul line to the head pin (1-pin). About 15 feet (4.57 m) from the foul line are a set of guide arrows. The lane is 41.5 inches (1.05 m) wide and normally consists of 39 wooden boards or a synthetic material. The bowling lane has two sets of approach dots; from the foul line back to the first set of approach dots is about 12 feet (3.66 m) and to the second set of approach dots is about 15 feet (4.57 m) (an additional 3 feet (0.91 m)). Although this figure varies, the lane is protected by about 18 ml of oil. The PBA events use about 30 ml of oil, and the PWBA events use 25 ml. The oil starts from about 4 inches from the foul line and is applied for about 38 feet (11.58 m) down the lane from that point.

Pins

Position of the ten pins from above.

USBC rules specify that a pin must be 15 inches (38 cm) tall and about 4.7 inches (12 cm) wide at its widest point, where a rolling ball would make contact. There are additional measurements which delineate the shape. The weight of a single pin must be at least 3 pounds, 6 ounces (1.47 kg) and no more than 3 pounds, 10 ounces (1.64 kg). Within a set of ten pins, the individual weights may vary by no more than 4 ounces (113.4 g), if made from wood or plastic coated, or just 2 ounces (56.7 g) if synthetic. The top of the pin shall have a uniform arc with a radius of 1.273 inches (32.3 mm), ± 1/32 inch (31.5 – 33 mm).

The USBC also has regulations governing the weight distribution of the pin from top-to-bottom. Pins are allowed one or two “voids” (holes) in the belly area (which can be viewed if the pin is cut in half from top-to-bottom). The voids are needed to balance the narrower top half of the pin with the wider bottom half. Without them, the pins would be too bottom-heavy to fall properly when struck.

The pins must show the name and mark of the maker, either “USBC Approved” or “BTBA Approved” and appear uniform.

The head pin or 1 pin stands on board 20 of the lane.

Bowling ball

The circumference of the ball must not be more than 2.25 feet (0.69 m), and the ball cannot weigh more than 16 pounds (7.26 kg). The ball must have a smooth surface over its entire circumference except for holes or indentations used for gripping the ball, holes or indentations made to bring the ball back into compliance with weight-distribution regulations, identification letters and numbers, and general wear from normal use.

For much of the history of bowling, bowling balls were made using a three piece construction method. Starting in the mid 1990s, however, most manufacturers switched to a two-piece method. In response to these innovative ball designs, the American Bowling Congress placed further restrictions on the technical characteristics of the ball such as the radius of gyrationand hooking potential.

Rules of play

A game of bowling consists of ten frames. In each frame, the bowler will have two chances to knock down as many pins as possible with his bowling ball. In games with more than one bowler, as is common, every bowler will take his frame in a predetermined order before the next frame begins. If a bowler is able to knock down all ten pins with the first ball, he is awarded a strike. If the bowler is able to knock down all 10 pins with the two balls of a frame, it is known as a spare. Bonus points are awarded for both of these, depending on what is scored in the next 2 balls (for a strike) or 1 ball (for a spare). If the bowler knocks down all 10 pins in the tenth frame, the bowler is allowed to throw 3 balls for that frame. This allows for a potential of 12 strikes in a single game, and a maximum score of 300 points, a perfect game.

Scoring

In general, one point is scored for each pin that is knocked over. So if a player bowls over three pins with the first shot, then six with the second, the player would receive a total of nine points for that frame. If a player knocks down 9 pins with the first shot, but misses with the second, the player would also score nine. When a player fails to knock down all ten pins after their second ball it is known as an open frame.

In the event that all ten pins are knocked over by a player in a single frame, bonuses are awarded.

A ten-pin bowling scoresheet showing how a strike is scored.

• strike: When all ten pins are knocked down with the first ball (called a strike and typically rendered as an “X” on a scoresheet), a player is awarded ten points, plus a bonus of whatever is scored with the next two balls. In this way, the points scored for the two balls after the strike are counted twice.

Frame 1, ball 1: 10 pins (strike)

Frame 2, ball 1: 3 pins

Frame 2, ball 2: 6 pins

The total score from these throws is:

• Frame one: 10 + (3 + 6) = 19
• Frame two: 3 + 6 = 9

TOTAL = 28

Two consecutive strikes are referred to as a “double.” (image unavailable)

A double's pinfall is:

Frame 1, ball 1: 10 pins (Strike)

Frame 2, ball 1: 10 pins (Strike)

Frame 3, ball 1: 9 pins

Frame 3, ball 2: 0 pins (recorded as a dash '-' on the scoresheet)

The total score from these throws is:

Frame one: 10 + (10 + 9) = 29

Frame two: 10 + (9 + 0) = 19

Frame three: 9 + 0 = 9

TOTAL = 57

Three strikes bowled consecutively are known as a “turkey” or “triple.” (image unavailable)

A triple's pinfall is:

Frame 1, ball 1: 10 pins (Strike)

Frame 2, ball 1: 10 pins (Strike)

Frame 3, ball 1: 10 pins (Strike)

Frame 4, ball 1: 0 pins (Gutterball)

Frame 4, ball 2: 9 pins

The total score from these throws is:

Frame one: 10 + (10 + 10) = 30

Frame two: 10 + (10 + 0) = 20

Frame three: 10 + (0 + 9) = 19

Frame four: 0 + 9 = 9

TOTAL = 78

Any longer string of strikes is referred to by a number attached to the word “bagger,” as in “four-bagger” or “five-bagger” for four or five consecutive strikes. Recently, the event of bowling four consecutive strikes has also been called a “sombrero” or “ham bone.” This terminology is used most often when a bowler is “off the strikes.” (i.e. has previously bowled a string of several strikes but failed to strike on his most recent ball.) When a player is “on the strikes,” a string is often referenced by affixing “in a row” to the number of strikes bowled consecutively. Six strikes in a row are sometimes referred to as a “six pack.” Six strikes and nine strikes in a row can also be referred to “Wild Turkeys” and “Golden Turkeys” respectively. Any string of strikes starting in the first frame or ending “off the sheet” (where all of a bowler’s shots from a certain frame to the end of the game strike) are often referred to as the “front” or “back” strikes, respectively (e.g. the “front nine” for strikes in frames 1-9, or the “back six” for strikes in frames 7, 8, and 9 with a turkey in the tenth). A “Perfect Game” or 12 strikes in a row is also colloquially referred to as the “Thanksgiving Turkey.”

A player who scores multiple strikes in succession would score like so:

Frame 1, ball 1: 10 pins (strike)

Frame 2, ball 1: 10 pins (strike)

Frame 3, ball 1: 4 pins

Frame 3, ball 2: 2 pins

The score from these throws are:

• Frame one: 10 + (10 + 4) = 24
• Frame two: 10 + (4 + 2) = 16
• Frame three: 4 + 2 = 6

TOTAL = 46

The most points that can be scored in a single frame is 30 points (10 for the original strike, plus strikes in the two subsequent frames).

A player who bowls a strike in the tenth (final) frame is awarded two extra balls so as to allow the awarding of bonus points. If both these balls also result in strikes, a total of 30 points (10 + 10 + 10) is awarded for the frame. These bonus points do not count on their own, however. They only count as the bonus for the strike.

A ten-pin bowling scoresheet showing how a spare is scored.

• spare: A “spare” is awarded when no pins are left standing after the second ball of a frame; i.e., a player uses both balls of a frame to clear all ten pins. A player achieving a spare is awarded ten points, plus a bonus of whatever is scored with the next ball (only the first ball is counted). It is typically rendered as a slash on scoresheets in place of the second pin count for a frame.

Example:

Frame 1, ball 1: 7 pins

Frame 1, ball 2: 3 pins (spare)

Frame 2, ball 1: 4 pins

Frame 2, ball 2: 2 pins

The total score from these throws is:

• Frame one: 7 + 3 + 4 (bonus) = 14
• Frame two: 4 + 2 = 6

TOTAL = 20

A player who bowls a spare in the tenth (final) frame is awarded one extra ball to allow for the bonus points.

Correctly calculating bonus points can be difficult, especially when combinations of strikes and spares come in successive frames. In modern times, however, this has been overcome with automated scoring systems, linked to the machines that set and clear the pins between frames. A computer automatically counts pins that remain standing, and fills in a virtual score sheet (usually displayed on monitors above each lane). However, even the automated system is not fool-proof, as the computer can miscount the number of pins that remain standing.

The maximum score in a game of ten-pin is 300. On Feb. 2, 1997, University of Nebraska sophomore Jeremy Sonnenfeld became the first person ever to roll three perfect games of 300 in a three-game series (as approved by the American Bowling Congress). This has only been achieved a handful of times since.

In Britain, the youngest bowler ever to achieve a perfect single game score of 300 (12 consecutive strikes), in a sanctioned competition was 12 years, 71 days old Elliot John Crosby, at AMF Purley in South London, England in the Surrey County trials on January 7 2006. Crosby beat the previous British 300 shooter record holder Rhys Parfitt by more than a year. Parfitt was 13 years, 4 months when he achieved a 300 point game at the London international tenpin bowling tournament in 1994. In the United States, the youngest ever bowler to achieve this in a sanctioned competition is two-handed bowler Chaz Dennis of Columbus, Ohio. He achieved this competing in the Hillcrest Preps-Juniors league at Hillcrest Lanes in Columbus, Ohio on December 16, 2006 at 10 years, 88 days old. Dennis was 20 days younger than the previous record-holder, Michael Tang of San Francisco, California, who set his record when he was 10 years, 108 days old competing in the Daly City All Stars Scratch Trios League at the Sea Bowl in Pacifica, California.

Scoring: Alternative method

There does exist an alternative method for keeping score. It is used by scoreboards at some tournaments, and by some bowling software programs. It is exactly the same as the conventional scoring described above, except that the score is always current (i.e. what the player would have if s/he never knocks down another pin).

The basic rules are as follows:

• Spare = Points scored for the next ball are doubled (2 points per pin knocked down);
• Strike = Points scored for the next two balls are doubled (2 points per pin);
• Two or more strikes in a row = Points scored for the next ball are tripled (3 points per pin). If this roll is not a strike then the next ball is counted with doubled points.
• If all ten pins are not knocked down, no bonuses are scored on subsequent throws - only actual pinfall.

Let's go through a sample game:

Frame 1 = Let's say our bowler leaves a 10-pin and picks up the spare. Score 10.

Frame 2 = Strike. Score 20 (10x2). Total = 30.

Frame 3 = Bowler leaves a 7-10 split and picks up one of the remaining pins. Score 16 on the first ball (8x2) and 2 on the second. Total = 48.

Frame 4 = Bowler throws an errant shot and the ball lands in the gutter, but knocks down all ten pins on the next ball. However, because it is the second ball of the frame only a spare is earned - and because the previous frame was open, all pins count face value. Score 10. Total = 58.

Frame 5 = Bowler leaves a solid 7-pin and picks it up. Score 18 for the first ball (9x2) and 1 for the second. Total = 77.

Frame 6 = Strike. Score 20 (10x2). Total = 97.

Frame 7 = Strike. Score 20 (10x2). Total = 117.

Frame 8 = Strike. Score 30 (10x3) because our bowler was working on a double. Total = 147.

Frame 9 = Strike. Score 30 (10x3). Even though three strikes in a row had been thrown previously, our bowler is still considered to have a double working because the bonuses for the strike in the sixth have expired. Total = 177.

The scoring for the tenth frame goes as follows:

• If a spare was earned in the ninth frame, score double on the first ball in the tenth frame and face value (single) for the second and third balls, if there is a third ball.
• If a strike was earned in the ninth frame, score double on the first two balls in the tenth frame and single on the third ball.
• If strikes were earned in the 8th and 9th frames (as in our sample), score triple on the first ball in the tenth, double on the second ball, and single on the third.
• If the ninth frame was open (all 10 pins not down on 2 balls), then all three balls in the tenth count single.

Back to our game—Frame 10 = Strike. Score 30 (10x3). Total = 207. As for the two bonus balls, let's say our bowler leaves a 6-10 and picks it up for the spare. Score 16 for the first fill ball (8x2) and 2 for the second.

Final score = 225. This game is an illustration of how dramatically a player's score can skyrocket as a result of stringing together several strikes.