The Lane and Equipment

The playing surface is a lane, 60 feet long from the foul line to the head pin 42 inches wide. On either side of the lane are gutters; if the ball goes off the edge of the lane, it will drop into the gutter and be carried past the pins. The approach is an area 15 feet long, ending at the foul line. The bowler, in making the approach, must not step over the line; 60 feet beyond it is the headpin. The pins are arranged in four rows, with one pin in the first row, two in the second, three in the third, and four in the fourth. They are numbered 1-10; the pins themselves don't carry specific numbers, but the spots on which they are placed do.

The regulation pin is made of hard maple; it is 15 inches high and has a diameter of 2 ¼ inches at the base and a circumference of 15 inches at its widest point. Weight must be between 2 pounds, 14 ounces and 3 pounds, 10 ounces. The regulation ball is of solid composition, has a circumference of no more than 27 inches, and weighs 10 to 16 pounds. A ball may have two or three finger holes; most bowlers use the three-holed ball, inserting the two middle fingers and the thumb into the holes.

Bowling in ordinary shoes isn't permitted, because it can damage the lanes. The peculiarities of the sport demand an unmatched pair of shoes. The right-handed bowler wears a left shoe with a relatively slippery sole, usually of hard leather or vinyl, and a right shoe with a rubber sole that will help "brake."

Progress of Play

A game is made up of 10 frames. Each frame represents one turn for the bowler, and in each turn the player is allowed to roll the ball twice. If the player knocks down all the pins with the first roll, it is a strike; if not, a second roll at the pins still standing is attempted. If all the pins are knocked down with two balls, it is a spare; if any pins are left standing, it is an "open frame."

If a bowler commits a foul, by stepping over the foul line during delivery, it counts as a shot, and any pins knocked down are re-spotted without counting. If pins are knocked down by a ball that has entered the gutter, or by a ball bouncing off the rear cushion, they do not count, and are re-spotted.

Scoring

Frame
There are ten frames in one game. You have two chances to knock down the ten pins in each frame (see the explanations for strike and spare). Note that the tenth frame rewards you with a final bonus ball if you convert your spare (or make two strikes). You can thus throw nine strikes in the first nine frames and, if you get another two in the tenth, the bonus ball means the most strikes you can have in one game is twelve. This is called a perfect game..
Spare
Getting all ten pins down with one ball is not as easy as it seems! So, if you leave one or more pins standing after your first delivery, you get a second chance to knock all the pins down, this is your "spare" shot. If you knock all remaining pins down on the second shot you have made your spare. A spare is marked on the scoresheet with a "/". It takes skill to consistently make spares and the scoring system rewards you by adding in the pins from the next ball into the current frame. See also split.
Strike
When the bowler knocks down all ten pins with the first delivery of the ball it is called a strike. Clearly your score goes up by ten, but like a spare, you get a bonus - your next two deliveries are added to the score. Stringing strikes together will raise your score dramatically (See turkey). Marked on the scoresheet with an "X".

Average
Your average is the sum of all your games divided by the number of games played. You can use your average as a way of recording your improvement - set a goal of raising your average game, say 10 pins a season, until you reach the level of par bowlers.
Clean Sheet
If you make ALL your spares in the game it is called a clean sheet. Making your spares is the simplest way to raise your average on the way to becoming a scratch/par bowler.
Dutch 200
Scoring spare-strike-spare strike for the entire game results in a score of 200 exactly.
Foul
The foul line is drawn across the lane to separate the approach from the start of the lane. Putting your foot over the foul-line means you don't get the score for that delivery: on the first delivery you must re-rack the pins. It is marked on the scoresheet with an "F".
Open Frame
If you fail to make your spare, i.e. knock all pins down in two shots it is called an open frame
Par
Consistently making all your spares will give you an average in the 180 to 190 range. When you develop your game so that you can start to string strikes together your score will go up and you will start to approach the 200 or 210 mark, which many have likened to being a "scratch" golfer.
Perfect Game
If a bowler manages to score twelve strikes in a row, in the same game, the score is 300 (the highest possible) and it is called a perfect game.

EXAMPLE 1

In Example 1 we omitted strikes and spares for simplicity. Each frame is totaled and added to the cumulative score.

EXAMPLE 2

In Example 2 we learn how to score spares and open frames together. A spare is scored as 10, plus the pinfall of the next ball rolled. This total is added to the cumulative score.

Frame 1) Count 9 pins
Frame 2) Spare (10), plus next ball (6) added to score = 25
Frame 3) Count 7 pins and add to score = 32
Frame 4) Spare (10), plus next ball (8) added to score = 50
Frame 5) Count 9 pins and add to score = 59
Frame 6) Spare (10), plus next ball (0) added to score = 69
Frame 7) Spare (10), plus next ball (8) added to score = 87
Frame 8) Count 8 pins and add to score = 95
Frame 9) Spare (10), plus next ball (8) added to score = 113
Frame 10) Add (10), plus 8 to score = 131

EXAMPLE 3

In Example 2 we learn how to score strikes, spares and open frames together. As previously demonstrated, a spare is scored as 10, plus the pinfall of the next ball rolled. A strike is scored as 10, plus the pinfall of the next 2 balls rolled. This total is added to the cumulative score.

Frame 1) Strike (10), plus next 2 balls (3)(7) = 20
Frame 2) Spare (10), plus next ball (6) added to score = 36
Frame 3) Count 7 pins and add to score = 43
Frame 4) Strike (10), plus next 2 balls (10)(10) add to score = 73
Frame 5) Strike (10), plus next 2 balls (10)(2) add to score = 95
Frame 6) Strike (10), plus next 2 balls (2)(8) add to score = 115
Frame 7) Spare (10), plus next ball (9) added to score = 134
Frame 8) Count 9 pins and add to score = 143
Frame 9) Spare (10), plus next ball (10) added to score = 163
Frame 10) Strike (10), Strike (10), Strike (10) = 193