The Petersen Point System is often confused with other point systems. This is because there seems to be no universally accepted definition of Peterson Bonus Points and varies between leagues or tournaments.

One definition that seems to be used most often is where a player or team receives one point for every xx number of pins scored.

Usually, You get 1 point for every "Block" of 25, 50 or 100 pins of total scratch or handicap scores. The bonus is then calculated by taking the player's or team's total scores (scratch or handicap) and dividing it by the block size.

For example, if you used a 50 pin block and bowled a 575, it would be 11 points. (575 divided by 50= 11.5, with the fraction dropped).

Another variation of the Petersen point system, is where points are awarded for each "block" of pins scored. For examples, if the "block" is defined as 50 pins, and you shoot 575, you would receive 11 Petersen points. In addition, bonus points are awarded for victories. (A variation of this is where you don't drop the fraction.)

Example if you won 2 games (out of 3) plus series and 10 points were awarded for each victory, you would receive a total of 41 points for the evening. (20 points for the 2 games and 10 for the series. 11+20+10=41)

From Bowl.com

LOUIS PETERSEN

Chicago

Born: Sept. 23, 1883

Died: June 20, 1958

Inducted 1963

A scoring system and a bowling tournament have etched Petersen's name indelibly in the upper strata of bowling contributors. He started his famous Petersen Classic in 1921 and that event's popularity has grown each year. Petersen also originated the point system bearing his name. He also was a founder of the Bowling Proprietors Association of America in 1932 and a prime mover of high school bowling.