Ridenour 3 pin 10 pin
Is that the 3 pin carrying the 10 pin? A study in the light pocket strike
Many of us have seen the 6 pin hitting into the 10 pin or the head pin hitting the left side wall shooting across and taking out the 10 pin. However, what is the 3 pin's job in a light pocket hit and how does that affect the carry percentage of a light pocket hit?
Using a high speed camera and four 1000-watt studio lights, new USBC research shows us in slow motion the exact way a bowling ball carries a rack of pins and the path it takes into and out of the pocket.
The USBC has publicized that a pocket strike occurs at board 17 to 18 with an entry angle between 4 to 6 degrees. These statistics provide the highest strike percentage of every combination of entry board and entry angle. A variety of factors have influenced the growth of the average entry angle into the pocket. Due to this, bowlers have noticed that the pocket has increased in size. Is this due to the increased entry angle combined with carry or is the pocket actually getting bigger?
We can see in video 1 that this is a typical flush pocket strike with the ball starting at board 17 going into the pocket. After the ball hits the head pin, it causes the ball to deflect into the 3 pin, then into the 5 pin and finally just clipping the 9 pin and going off the back of the pin deck around board 19 between where the 8 and 9 pins stood.
This is the prototypical flush pocket strike for which bowlers strive.
The bowler in videos 2 and 3 uses the same ball on the same lane condition and plays the same line. In video 2, the ball is at approximately board 16.5 at a reasonably-high entry angle when it enters the pocket. The ball will deflect into the 3 pin which sends the 6 pin in front of the 10 pin. The 3 pin will then knock over the 9 pin and the ball will exit the back of the pin deck around board 14. This is a classic 10 pin leave.
Video 3 results in a strike. However, the ball is a little further right but has approximately the same entry angle into the pocket. The ball in video 3 starts at around board 16 and hits the head pin. The ball then deflects into the 3 pin. The trick to carrying a strike on this light pocket hit is the 3 pin, which deflects into the 9 pin and then deflects once again into the 10 pin. The ball will finish in the pocket a little further left than in the 10 pin leave; however, the ball started further right than the other ball did.
This is a difficult sequence to pick out with the naked eye, but the high-speed camera shows it clearly.
The next two videos show a different bowler, but curiously enough the same results occur as in videos 2 and 3. The different bowlers in videos 3 and 5 strike on light hits as the balls deflect more toward the center of the lane. But the balls that hit higher in the pocket (videos 2 and 4) left 10-pins with the balls exiting the pin deck further right. The bowler in videos 4 and 5 played a much straighter line than the bowler in videos 2 and 3, but the results were the same.
As we see in video 1, what is considered a traditional, high flush strike still occurs around board 17 to 18 as proven by previous USBC data. The light pocket hit is due more to the deflection of the 3 pin into both the 9 and 10 pins than the 6 pin coming off the wall into the 10 pin as commonly thought.
USBC will conduct more testing this season using the high-speed camera and lighting system to further investigate entry and exit angles from the pin deck and to determine how that affects carry percentages.
This article is courtesy of USBC