CONTRARY TO what some would have you believe, pinfall, with rare exception, is quite predictable. With the use of sophisticated equipment and modern technology in testing centers, researchers are proving there are good reasons why pins fall on some shots and not on others. Even more, this underscores a bowler's need to strive to understand the causes and effects of pinfall reaction in order to attain a higher standard of ability.

Furthermore, these experiments confirm a long and strongly held view; namely, "Regarding the path of the ball, the steeper the angle of entry into the pocket, the less the ball deflects off the head pin to the right, and the more it deflects off the 3-pin to the left (for right-handers)."

In turn, this upholds the conviction that, "The higher the coefficient of friction, which easily produces more hook (and therefore more angle of entry), the easier the game becomes." This providing you can get the ball to the pins before it rolls out.

Regardless of how much a ball hooks, if it hooks early it cannot effect a strong angle of entry into the pocket; this because the geometry of the lane, which has a much greater length than width, precludes this from happening. On the other hand, if you can stave off the ball's precession rate (the hooking process) until it is well down the lane, extreme angles of entry can be realized if the backend of the lane exhibits a high-friction surface. For this reason, a lane condition that is well oiled over the first 35 feet and "stripped dry" over the remaining 25 feet to the head pin is a bowler's "strike bonanza" - something akin to shooting ducks in a confined area.

Let's consider the basic pattern of pinfall for a strike. The ball hits the 1-3 pocket, sending the 3-pin into the 6-pin which, in turn, moves onto the 10-pin. Meanwhile, the head pin sets off a chain reaction by sending the 2-pin into the 4-pin, which, in turn, hits the 7-pin. The ball, having deflected off the head pin, now deflects off the 3-pin into the 5-pin, which, in turn, moves onto the 8-pin. At the same time, the ball (after hitting the 5-pin) deflects toward the 9-pin (which most often has already been hit by the 3-pin deflecting off the 6-pin). A shot entering the pocket straight on (0-degree angle) could possibly produce the above chain of events, but this is highly unlikely because the ball from this angle is prone to deflect too strongly off the head pin.

When the ball does deflect too strongly off the head pin, several things normally happen. To begin with, the ball hits more onto the front of the 3-pin with a left-to-right angle, thus failing to counter-deflect appropriately off the 3-pin, which results in its missing the 5-pin. In consequence, the 5-pin does not take out the 8-pin. At the same time, the 3-pin, now moving more forward (toward the pit) than diagonal, contacts the 6-pin too much on the side, thus sending it in front of the 10-pin instead of into it.

Once becoming familiar with the normal strike pattern, a bowler can then understand what has gone wrong when a pin remains standing on a pocket hit. For example, if the 10-pin is left, obviously there was an error involving the 3-6-10 chain of the pinfall system. And because the cause of such a leave is most often attributable to too much ball deflection off the head pin, a stronger angle of entry to the pocket is then called for in order to correct the problem.

The good and bad ramifications of angle are felt with every shot, particularly with those that deal with the pocket. For example, moving the 5-pin off the 8-pin and into the 7-pin indicates the angle was sufficient (in conjunction with other factors), while sliding the 5-pin in front of the 8-pin indicates insufficient angle. A 5-7 leave tells the player deflection was substantial and steeping the ball's angle further needs to be considered.

This brings up another concern. On a "stripped" lane surface, particularly as serviced in recent years, it is possible to create an angle that is too extreme. Repeated solid 8- and 9-pin leaves, or freakish leaves like a 7-9 leave on pocket hits (for right-handers), indicate that the normal pinfall pattern is being altered by the severity of the ball's angle of entry into the pocket, as well as attesting that the modern pin is more resilient and today's "exotic" balls react more strongly.

In this regard, one should also keep in mind that of greater importance than pocket angle is getting the pins to react in the ultimate way with one another, by getting them to leave the lane more horizontally (laying down) and laterally (more toward the kickbacks), instead of having them move off the lane more vertically and more in the direction of the pit. However, this factor is not directly related to a ball's angle of entry, but rather to its roll characteristics.

One final note. Though all pins are formidable at times, what usually prevents us from striking on a pocket hit is the 4-pin, or the 10-pin. In the case of the 4-pin, it is usually left standing when the ball enters the pocket somewhat high and the hand at the point of release was somewhat closed (9 o'clock position with the thumb, for right handers), which, in turn, does not allow for a roll characteristic that would "trip" the 4-pin. On the other hand, the 10-pin is usually left when the ball moves off the front of the hand (rather than moving off the inside of the hand), thus limiting the angle of entry into the pocket, which, in turn, causes the 3-pin to move more forward toward the pit toward the 6-pin. In consequence, the 6-pin is now clipped on the left side by the 3-pin, which sends it to the kickback and around the 10-pin instead of into it.