When playing a standard game of 10-pin bowling, there are a few scenarios to keep in mind if you wish to keep an accurate score.
The most common scoring scenario for average bowlers is called Open Frame Scoring. An Open Frame occurs if the bowler uses both of their rolls and fails to knock down all ten pins (0-9 pins were knocked down). Whenever this happens without a preceding spare or strike, the bowler will be awarded points equal to the number of pins they just knocked down. For example, if a bowler begins a game by knocking down 6 pins on their first roll of a turn and 3 pins on their second roll of a turn, then the bowler will be awarded 9 points.
Most people know that the amount of points the bowler is awarded corresponds with the amount of pins knocked down on a given turn. However, scoring calculations are not quite as obvious after a bowler gets a spare. In bowling, a spare happens when the bowler uses both of their rolls in a given turn to knock down all 10 pins. In cases like these, the bowler is awarded 10 points for knocking down all 10 pins, while also earning double points on their first roll on the very next turn. For further clarification, take a look at this scenario: A bowler achieves a spare in Frame 1 by knocking down 8 pins on her first turn and the last 2 pins on her next roll. In Frame 2, the same bowler knocks down 6 pins on her first roll and 2 on her next roll. At this point, the bowler is rewarded with 16 points in Frame 1 (10 from the spare + 6 from first roll on next turn). In addition, the bowler added 8 points for knocking down 8 pins, bringing the bowler's total score to 24 through the first two frames.
Another scoring scenario that requires slightly different calculations occurs after a bowler achieves a strike. In bowling, a strike occurs when the bowler knocks down all 10 pins in a single roll. In situations like this, the bowler is awarded 10 points for knocking down all 10 pins; however, they also earn double points for their next 2 rolls. For Further clarification, take a look at this scenario: A bowler earns a strike in Frame 1 by knocking down all 10 pins on his first roll. In frame 2, this same bowler knocks down 5 pins on his first roll and 4 pins on his second roll. At this point, the bowler is awarded with 19 points in Frame 1 (10 from the strike + 9 from the sum of the next two rolls). In addition, the bowler is awarded 9 points for knocking down 9 pins in frame 2, bringing his total score to 28 through the first 2 frames.
A perfect score in bowling is 300. The only way to achieve this score is to roll 12 straight strikes, 1 strike for each of the first 9 frames and then 3 strikes in the final frame. If a bowler achieves this impractical feat, then each and every frame will have been worth 30 points bringing the 10 frame total to 300.
If a player rolls multiple strikes in a row, the same general described above takes effect, meaning the bowler will be awarded double points for their next two rolls. The only difference is that these next two rolls would take place across two separate frames. Take a look at this scenario: A bowler rolls 2 strikes in their first 2 frames of a game. Then, the bowler knocks down 5 pins on their first roll of frame 3 and 2 pins on their second roll of frame 3. The scoring would be as follows: 25 points for frame 1 (10 point for initial strike + 10 points for second strike + 5 points for first roll on frame 3), 17 points for frame 2 (10 points for frame 2 strike + 7 points for both rolls in frame 3), 7 points for frame 3 (7 pins knocked down = 7 points). In total, the player's score through these first three frames would be 49 (25+17+7).
For novice bowlers, a score range of around 100-140 is generally considered good. This would usually include 1-2 strikes, 2-4 spares, and 4-6 open frames. For intermediate bowlers, a score range of 150-190 is fairly common. This scoring range usually includes 2-4 strikes, 3-5 spares, and 2-5 open frames. For advanced bowlers, a scoring range of 200-250 is normal. This range usually includes 5-8 strikes, 2-3 spares, and 1-2 open frames.