The Science Of Tennis
Book Link Authors: Brody, Cross and Lindsay
Sweet words they'd be to any author reading a reviewer’s summarization: “This is a book that you can’t put down once you pick it up”.
With a twist, this is a book you can’t pick up once you put it down. The package it came has a stated weight of 3.13lbs (or 1.42kg). Imagine, if you will, lumbering such a weight as a reading material to engage in on the train or in a bus.
Admittedly, the title of the book arrests your interest if you are a believer that knowledge (read that as technology) is power and it can give you the competitive edge in almost anything (read that as tennis). It is however quite a cumbersome volume to sieve through just to pick out the gist of it findings. In fact, you’ll soon realize that it reads like a textbook for students offering Physics as a subject at ‘A’ level. In keeping with a subject as dry as physics, the book is a mine-field of photographs, mathematical formulas, diagrams, graphs, and flow-charts describing the physical phenomenon that is being investigated. Complex if not obtuse scientific concepts such as Vertical Angular Acceptance and Coefficient of Restitution are expounded with enthusiasm. Most readers may find the concepts difficult to grasp.
Somewhat dated by now, it is a pity that the book does not cover the latest technologies in racquet materials and strings and there is apparently no co-ordination between the authors to merge and present their findings collectively so as to eliminate overlapping or redundancy. Not every reader has a physicist’s mind. The less technically minded will have to comb the entire text to unearth an insight or two.
Comprising over 40 different articles, they are the results of research, investigation and experiments conducted scientifically by highly respectable people - two physicists and a publisher. It objectively clears the air about many misconceptions the layman has about tennis per se and most of the findings are contrary to popular beliefs.
Some pickings from the book:
- A standard Type 2 (that’s the type in common use) professional tennis ball should rebound 55% when dropped from a height of 100 inches onto a concrete surface.
- The ITF has recently allowed the use of a new Type 3 ball, which is slightly lighter and softer but 6% larger in diameter. (I believe it was to slow down the game but the idea didn’t latch on and Type is not available locally)
- Even though you can’t see it with the naked eye, during impact, the ball squashes by as much as 50% and the frame bends out of shape.
- The number one determinant of serve speed is the velocity of the racquet at the impact point on the ball.
- Professional players can serve almost as fast with an old wood racquet as with a modern graphite racquet – the difference is rarely more than 5%.
- Tennis has conflicting adages in “keep the ball on the loose stings longer for better control” and “tight strings give better control”. Lower tension will provide a little more power, and an open string pattern will also produce more power.
- String tension is largely a matter of preference. Lower string tension will give you more power but only 1% more.
- Stiff strings normally increase jarring since they cause the handle to vibrate more and to slam into the hand.
- ‘Control’ cannot be measured. No one knows how to.
- All racquets have essentially the same power. A common view is that a stiff frame generates more shock at impact. In reality, it vibrates less and feels better as they is less shock.
- A racquet also needs stability when impacting the ball, thus at a certain point (e.g. below 8 oz), a lighter racquet can never compete with a heavier one in terms of stability.
- The number one way of improving service percentage is by hitting the ball at a higher elevation. An increase of 6 inches in height increases the acceptance window by almost 30%.
- By the time a 110 mph service gets to the other baseline, it has slowed down to 55 mph due to air resistance and friction from the bounce.
- Moving 5 feet behind the baseline gives the receiver 10% more time to react to the service.
- Unlike the bounce of balls in most sports, the angle of reflection does not equal the angle of incidence for tennis balls rebounding from a racquet.
- Higher string tension actually increases string life because at higher tension there is less string movement, hence less “sawing” and “notching”.
- A ball hit with topspin arrives at the receiver spinning between 50 to 100 revolutions per second
- Perimeter weighting drastically reduces shock
- Backspin groundstrokes are easier to hit than topspin, but have much less tolerance for error.
- Pros do not use the racquets they are touted to endorse – it’s just a paint job
- (to be continued)
posted by Victor Lai @ 5:09 PM
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