Bowling handicap calculator

How to use the bowling handicap calculator

1. Enter the bowler's average. If you do not know it, type your recent game scores under Average from game scores and press Use this average.
2. Set the basis score and percentage from your league rules, or tap one of the common values.
3. The handicap appears straight away, with the math shown so you can check it against the league sheet.
4. Optional: list every bowler's average to get the team handicap, or type tonight's scratch scores to see each game and the series with handicap.

The handicap formula

handicap = (basis score − average) × percentage, fractions dropped

Handicap gives a less experienced bowler a fair chance against a stronger one by adding pins to each game. The basis score is a target, usually somewhere from 200 to 230, and the percentage factor sets how much of the gap is made up, usually 80% to 100%. At 100%, two bowlers who bowl exactly their averages will finish level.

Two details matter. First, the USBC rule is that fractions are dropped, not rounded, both for averages and for handicaps. Second, if the average is at or above the basis score, the handicap is zero, never negative.

Worked examples

A full night: a bowler with games of 145, 162 and 151 has 458 pins in 3 games, an average of 152.67, which becomes 152. At 90% of 220 the handicap is (220 − 152) × 0.9 = 61.2, so 61 pins. If that bowler then rolls 158, 141 and 170 (a 469 scratch series), the handicap scores are 219, 202 and 231 and the handicap series is 469 + 3 × 61 = 652.

Choosing a basis and percentage for a new league

A higher percentage closes more of the gap between bowlers; 100% makes a match between a 140 and a 200 bowler a coin flip if both bowl their averages, while 80% still gives the stronger bowler an edge. The basis should sit at or above the top average in the league, otherwise your best bowlers get no handicap and the format stops being fair to them. Many leagues pick 90% of 220 as a middle ground, then keep the same values for the whole season so results stay comparable week to week.

Team handicap

In most leagues the team handicap is simply the sum of the handicaps of the bowlers in the lineup. A team with averages of 150, 172, 138 and 201 at 90% of 220 gets 63 + 43 + 73 + 17 = 196 pins per game. Some leagues instead work it out from the combined team average, which can differ by a pin or two because of the dropped fractions, so check your league rules.

Tips

• Use the same average for every game of a night. The new average only counts from the next session.
• When a team is missing a bowler, leagues usually use an absent score, often the bowler's average minus a set number of pins. That is a league rule, not part of the formula.
• Record each game on a printable bowling score sheet with average and handicap columns, or score live with the bowling score calculator.

How we tested it

The handicap code runs against automated Node tests: an average of 150 at 90% of 220 gives 63, an average of 221 at 90% of 220 gives 0, an average of 157 at 90% of 220 gives 56 (56.7 with the fraction dropped), and an average of 180 at 80% of 200 gives 16. The average helper is tested with games of 145, 162 and 151, which must give 152, not 153.