Strikes, spares, the 10th frame, the maximum still possible and handicap, by USBC rules
Updated October 2026
A game is ten frames. In frames 1 to 9 you roll twice unless the first ball is a strike. USBC Rule 2 sets the count: an open frame (fewer than 10 pins in two balls) scores the pins knocked down; a spare (all 10 in two balls) scores 10 plus the next ball; a strike (all 10 on the first ball) scores 10 plus the next two balls. Because bonuses use later balls, a frame with a mark is not finished until those balls are rolled, which is why scoresheets leave it blank for a while.
The default game, from a published scoring tutorial, is X, X, X, 7-2, 8/, F-9 (a foul on the first ball counts 0), X, 7/, 9-0, and X-X-8 in the 10th. Frame 1 is a turkey: 10 + 10 + 10 = 30. Frame 2: 10 + 10 + 7 = 20, total 57. Frame 3: 10 + 7 + 2 = 19, total 76. Frame 4 is open: 9, total 85. Frame 5 is a spare followed by a foul: 10 + 0, total 95. Frame 6: 9, total 104. Frame 7: strike plus 7 and 3 = 20, total 124. Frame 8: spare plus 9 = 19, total 143. Frame 9: 9, total 152. Frame 10: 10 + 10 + 8 = 28, final 180.
| Game | Entered as | Score |
|---|---|---|
| Perfect game | X X X X X X X X X X X X | 300 |
| All spares with 9 on the first ball, 9 on the bonus ball | 9/ 9/ 9/ 9/ 9/ 9/ 9/ 9/ 9/ 9/9 | 190 |
| All 9s, no spares | 9- 9- 9- 9- 9- 9- 9- 9- 9- 9- | 90 |
| Sample game from the scoring tutorial | X X X 72 8/ F9 X 7/ 90 XX8 | 180 |
| Strike, then 6 and 2 | X 62 (frame 1) | 18 |
| Spare, then 7 | 7/ 7 (frame 1) | 17 |
The 10th frame has no later frame to supply bonus balls, so they are rolled in the frame itself: a strike earns two more balls and a spare earns one, for up to three balls (Rule 2a). An open 10th frame ends after two balls. The bonus balls only count toward the 10th frame. That is why the best possible game is 12 strikes: nine in frames 1 to 9 and three in the 10th, 30 in every frame.
Enter a game in progress and the calculator assumes strikes for every remaining ball (a spare if you are mid-frame) to show the highest score you can still reach. After a first-frame 7-2, for example, the maximum is 279: nine strikes worth 30 each for frames 2 to 10, plus the 9.
Handicap lets bowlers of different averages compete. Most leagues use a percentage of the difference between a basis score and your average, dropping fractions: at 90% of 220, a 150 average gets (220 − 150) × 0.9 = 63 pins a game, and a 180 average gets 36. Leagues set their own basis and percentage, so check your league rules; an average above the basis gets no handicap.
Double: two strikes in a row; turkey: three (USBC calls it a triple). Split: pins left with the head pin down and a gap between standing pins, such as 7-10. Clean game: a strike or spare in every frame. Foul: crossing the foul line; the ball counts as zero.
It scores American tenpins only, not candlepin, duckpin or ninepin, and it does not judge fouls, dead balls or illegal pinfall, which follow other USBC rules. It does not keep a league average; use the average calculator for that.
Adding a spare’s bonus from the same frame. The bonus is the next frame’s first ball, not the second ball of the spare.
Counting a strike’s bonus as one frame. It is the next two balls, which after a strike may come from two different frames.
Scoring the 10th frame’s bonus balls as extra frames. They add only to frame 10.
Entering a 10 as a digit. Use X; the calculator reads each digit as one ball.