According to David Garber, Director of Coaching at the USBC, this should be taught to bowlers well before the age of 10 and in their very first bowling ball. The technique is to use the non gripping hand as your thumb and holding the ball in a position where your gripping hand can stay way under the ball. At the release point, that opposite hand come off at the last second allowing the gripping hand to lift from a point MUCH farther from the bottom than we can using just one hand. Most of us who bowl realize that the ability to keep your wrist cocked, letting go of the thumb smoothly and lifting is the reason why some can attain ferocious revolutions while others simply can't and this all happens in less than a second. Timing like this is in other sports too: baseball pitchers who throw from 88 to 100 mph, PGA golfers who drive from 260 to now almost 400 yards, hockey players with their slap shot, tennis serve, etc... all in less than a second. Incredible timing and talent.
In the near timeless tradition, bowling utilizes a 3 finger grip comprised of the thumb and two middle fingers. Aided by an experienced bowling pro shop who's job it is to measure, fit and drill bowling equipment based on the bowler's hand, flexibility and body style, the bowler must meld their muscle, gravity and centrifugal force to perform an approach culminating in releasing that ball. Span, pitch, thumb size and bevel along with grip pressure and timing allows some bowlers to attain high rev rates while others create less.
Now technology has come a long way in 20 years to give us a way around needing proper timing and talent: aluminum bats, graphite drivers and hockey sticks, skis, tennis rackets and running shoes just to name a few. The way this sport evens out the playing field is to allow the lower rev player products that significantly enhances their ball motion. Surface textures, denser cores, advanced layouts as well as proper coaching can prepare a bowler for nearly any playing condition.
I'll be the first to admit, from rubber house balls in the 70s to the soon to be released Mission 2.0, bowling has gotten easier for the average player to score higher. But how about the lower average player? I give a conventional plastic ball to juniors and people who average under 120. Should I give then an entry reactive and teach them two finger?
I wouldn't want to think that the years I've put into this sport will be unnecessary in the future by never drilling a thumb hole again. That it could be even easier to stand left and throw right on these already way too easy house patterns. If I start tooling the juniors down this path, ten years from now, will they still stand left and throw right? Will high performance balls go away because they can't keep them on the lane? Will proprietors have to flood the lanes and those with the traditional game won't be able to keep up? Will my shop close because anyone who buys a drill press can put two holes in a ball and glue grips?
Anybody remember Adam Sandler's Happy Gilmore and his newly invented hockey golf swing? It was a movie spoof but in a later movie, 50 First Dates, his assistant had a bunch of young kids. In this one particular golf scene, all 5 of them lined up their tee shots on a par 3 and simultaneously all hit 10 feet from the flag with that run up and hockey slap shot. Isn't that what's happening in real life? Aren't the young influenced by what they see? Tiger Woods ripped drives 15 years ago and now everyone coming out of college makes him seem like a short hitter.
We don't know the long term effects of this style. Your spine needs to be nearly parallel to the ground at release and your back leg has to be high in the air. Higher revs also demand speed control. A tad slow and it's over hooking while too hard or weak with the lift and it's a washout.
Do you know about the Bolivian team in South America that's entirely two finger? http://english.ntdtv.com/ntdtv_en/254/8130.html
Bowlers are aware and intrigued by this style but the choice over what we teach the future generations are being influenced by the need for instant results. Two handed is a way for the juniors to create ball reaction, to perhaps compete with the ultimate bowling killer, soccer. That sport has already siphoned tens of thousands of future bowlers out of the junior program each Saturday across the country.
Maybe that's why the USBC is so hot and heavy to make this the standard.