No Carry? - What's Your Entry Angle?
What do you get for your USBC sanction dues?
Maybe you haven't noticed much return for your money in the past (especially with the decrease in honor score awards), but USBC has undertaken some important studies of the science of bowling. One of the bits of data confirmed by these studies is the importance of entry angle for best pin carry. The chart below shows a rough picture of the strike percentage for different entry angles, based on where the ball enters the pins.
This shows the best strike percentage for all entry angles occurs when the ball center is 2-3" from the headpin center, or around the 17.5 board at pin impact. It also shows the 6 degree entry angle yields the highest percentage of strikes for virtually all distances from lane center. Notable also is the low percentage at about the 16-16.5 board. That's probably the pesky 10-pin (or 7 for lefties), where you knew the hit was just a little bit light. Maybe the most interesting item is the higher percentage around the 15.5 board (the light "shaker" or "mix" strike).
The major issue supported by this data is the importance of the 6 degree entry angle. Other data collected indicates that, although many other factors determine a bowler's average, entry angle increases in direct proportion to scoring average for all. Small improvements can mean a large jump in average - a change from 3 degrees to 4 degrees corresponds to a 30 to 40 pin increase.
