[MUSIC] In the last video you learned the difference between radical and incremental innovation. Now, I want you to take these concepts into practice classifying three tennis racquet innovations. Back in the 1960s, the dominant method of producing tennis racquets was to use laminated bent wood, as in modern IKEA furniture. This method of producing racquets had been in use since the 1930s. Here's a racquet from the 1930s. By the 1960s, there was little variation across racquets in their material, size or design. We would call this the dominant design. The Dunlop Maxply Fort and the Wilson Jack Kramer were two popular wood racquets. In 1963, Rene Lacoste, a French tennis player and businessman, caused a sensation by patenting the first tubular steel tennis racquet. Here it is. It was heavier than its wood counterpart, but a lot stiffer, and a player could impart a greater force on the ball in a single stroke, while a wooden one would have broken. One could not drill holes in the frame to thread the gut through, because the sharp edges of the steel would immediately cut it. Plastic grommets had not yet been invented either. So Lacoste threaded a polished steel wire around the frame, and the gut was threaded through it. It was marketed by Wilson under the name T-2000. Sales of the Wilson T-2000 took off as Billie-Jean King and Jimmy Connors started playing with it, changing the game of tennis forever. Where do you think the Wilson T 2000 lies in the radicalness spectrum, radical, incremental? Most of my on campus students agree that the Wilson T 2000 was a radical innovation, since so much changed with the new steel design and performance. It was not, however, that easy to play with and few amateurs liked it. You had to hit right in the middle for the racket not to twist and mishit. The next innovation was the Prince Classic, invented by Howard Head, an aeronautical engineer and inventor of the first pair of composite skis. After retiring, Head decided to take tennis lessons. He didn't improve, but he figured that it was because of the small sweet spot of the tennis racket, which is the area in the center of the racket. In 1975, Head then came out with a design of a racket with a much larger head size. To make it maneuverable at the sides, he had to switch to aluminum instead of steel or wood. But the aluminum frame was soft and easily twisted on impact, so Headinserted this large piece of plastic at the neck for stability. Although Head revolutionized the game of tennis for both athletes and amateurs, his own tennis skills did not improve significantly. Where do you think the Prince Classic lies in the radicalness spectrum, radical or incremental? Most agree that the Prince Classic was a radical technological change, although some say that just increasing the head size was not very radical. But the Classic was not just a question of increasing the size. Several manufacturers had tried creating larger rackets that were totally unusable, as they would twist too much outside the sweet spot, making for even bigger mishits than with the T 2000. Howard Head's solution was so technological new that he manage to obtain a patent on a range of oversized hits. To avoid patent infringement, competitors had to settle with making so-called mid-sized racquets instead. Nobody could compete in the oversize class as long as the patent was valid. And starting from zero market share, Prince tennis racquets were quickly adopted by more than 700,000 players and took 13% of the market in less than 4 years. Head's racquet was also the first to really allow the topspin stroke, revolutionizing the sport. The final innovation I want you to analyze is the Kuebler Resonanz. It's inventor, Sigfried Kuebler, was a German engineer who used to work on aerospace projects, familiar with high-tech material. The first Kuebler racquets were made from extruded aluminum in 1972. Later in 1980 came the 100% graphite racquets. But his most renowned racquet design was the wide bodied racquet called the Kuebler Resonanz of 1985. Kuebler's design goal was to produce a racquet stiff enough to return to its original state before the ball left the strings. While a soft racquet loses energy to the ball on impact, because it is still flexed when the ball leaves its strings, Kuebler realized that a stiff racquet would provide significantly more propulsion back to the ball. The resonance therefore had a four centimeter thick frame, coining the term Widebody, the first of its kind. Here's an example of the Widebody racket. You can see that the racket has a very thick frame compared to the Prince. Where do you think the Kuebler Resonanz lies in the radicalness spectrum, radical or incremental? You may consider this last innovation as incremental. Kuebler worked hard on the idea of having as stiff of a frame as possible to be able to return as much power as possible back to the ball. By that time, the idea of having a stiff frame was not new, but analyzed in a series of articles and later books written by Howard Brody and associates, on discussing the physics of tennis racquets. A rather obvious approach was to make the frame wider, or more aptly, thicker. By now you have an understanding of how to classify inventions as radical versus incremental. These examples of tennis racket innovations can also help you to see how users can contribute significantly to innovation. Because they were created not by existing tennis racket manufacturers, but by people from outside the industry. This was something we already discussed in module one and we will come back to discuss why this happens. In the next video, we'll go over yet another dimension to categorize innovations based on their impact on competitors' competences, stay tuned. 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