Tennis Racket Case What tennis related present can I get my Mum that isn't a racket?
My mum has started playing tennis a lot and has joined a club so I want to get her something tennis related for Christmas (pretty inappropriate time I know). She has an ok racket and case and some trackies and trainers but is there anything else I could get her? Or anything else by my description of her you think she would like?
Take care of your racket with the Butterfly B Table Tennis Racket Case! This padded case holds one ping pong paddle. A front mesh pocket is included for additional accessories.
The Killerspin Hard Table Tennis Racket Case features a semi-rigid padded polyester construction to keep your racket protected! This durable case includes interior elastic fasteners to keep your racket in place. A handy carrying strap makes transport easy and convenient.
The Joola Pocket Table Tennis Racket Case helps keep your racket protected! This durable nylon case features a double-walled padded interior. A ball storage pocket on the outside of the case holds up to 3 ping pong balls. The Pocket Case includes a carrying strap for convenience. Available in black, blue, and gray.
The Hardfull III Table Tennis Racket Case from Butterfly keeps your racket safe and secure during transport or storage. This hard shell case features an interior mesh pocket for additional accessories. An secure strap keeps your ping pong paddle in place! The Hardfull III zips shut and includes a carrying strap. It is available in 3 fun metallic colors: gold, silver, and black.
WallMonkeys wall graphics are printed on the highest quality re-positionable, self-adhesive fabric paper. Each order is printed in-house and on-demand. WallMonkeys uses premium materials & state-of-the-art production technologies...
The Blue Tennis Racket emblem is hand cast pewter. Each color is individually hand painted with durable enamel. This designer large pill box is well constructed of brushed steel and measures 2" x 2" x 5/8" with an inside divider to organize your supplements...
The Blue Tennis Racket emblem is made of hand cast pewter. Each color is individually hand painted with durable enamel. This attractive mirror pill box is constructed of aluminum in a matte finish. The case measures 2 1/2 " x 2 1/4" x 1/2" with an inside divider to keep supplements organized...
The Blue Tennis Racket Small pill box has a cast pewter emblem that is hand colored with durable enamel. The polished stainless steel pill box is 1 1/2" X 1 1/2" . Keep your everyday supplements, pain relief tablets or breath mints close at hand...
Why go piecemeal? Show your commitment to being a master Wii sportmans with the Ultimate Action Sports Pack. This bundle includes attachments for all the most popular Wii sports games.
All the items are easily interchangeable and lock securely to the
PS3 Move Remote. Designed for 2 players so you can compete and challenge all your friends and family and get the
true feel of the game...
Elegant designs, chic fabrics and unique detailing; make these bags a perfect choice for the fashionable tennis player on and off the court. Fits 2 oversized racquets. Includes matching cosmetic bag. Dimensions: 14...
The Killerspin Duffle bag has been designed with players needs in mind; intelligent, functional, and structural design coupled with cool styling. Its also waterproof and contains 2 large side gear pockets as well as an accessory or ball pocket as well.
The Blue Tennis Racquet luggage tag has a pewter emblem that is hand cast and colored with durable enamel. The leather has accent stitching on the front; the back has a privacy flat to cover your contact information or business card...
Take your table tennis game to the next level with the JOOLA USA Rossi Competition Table Tennis Paddle - Rossi Competition. Complete with a high-quality protective case, this racket paddle is built for serious competition...
Elegant designs, chic fabrics and unique detailing; make these bags a perfect choice for the fashionable tennis player on and off the court. Fits 2 oversized racquets. Includes matching cosmetic bag. Dimensions: 22L" x 9W" x 14...
Elegant designs, chic fabrics and unique detailing; make these bags a perfect choice for the fashionable tennis player on and off the court. Fits 2 oversized racquets. Includes matching cosmetic bag. Dimensions: 17...
Officially licensed by Nerf Add fun and realism to Wii sports games while promoting the safe use of the Wiimote Includes 3 Nerf safe attachments: a golf club a baseball bat and tennis racket
CTA DIGITAL WI-PPP Ping Pong Paddles for Wii. Two Foam Rubber Padded Paddles, Two Paddle Attachments that Snap into Handles, Authentic Feel, Lightweight, and Compatible with Wii Remote. Wii Motion Plus is not included.
Engineered for competitive play, this table tennis racket offers an ideal balance of speed, spin, and control. Highlights include a high-end, 5-ply blade and International Table Tennis Federation-approved rubbers that deliver extra power and spin...
Improve your next game of ping pong with the Butterfly 401 Shakehand Table Tennis Racket. Designed with extremely tacky Butterfly Yuki rubber on both sides and a softer 2.1mm sponge layer, the Butterfly 401 Shakehand Table Tennis Racket will deliver tremendous spin, speed, and a springy feel on all your shots...
Battery Powered Electric Tennis Racket Bug Zapper Swatter. Kill those pesky flying insects on contact with the hand held Electric Bug Zapper! This bug zapper is easy to use. Just press and hold the charging button, touch the grid to the insect, and the insect is killed on contact! With a tennis racket shape, it is lightweight and easy to hold and maneuver...
Tennis Racquet Calculator Synth keytar made by Corey Busboom
How Accurate is the Hawk-Eye System for Tennis Line Calls
We know and have seen how video analysis can be used to analyze a tennis players performance, but it can also be used in real time or almost real time to track the ball and even make close line calls. Of course I am talking about the "Shot Spot" or Hawk-Eye system.
If you have watched any Major Tennis since 2006, you will know exactly what Hawk-Eye is. The Hawk-Eye is used to make decisions on line calls that are challenged by the tennis player. Each player (or team if playing doubles) can challenge a line call on any point. They get a maximum of 2 incorrect challenges each set. If the set goes to a tie break an extra challenge is allowed. Basically the Hawk-Eye challenge enables the tennis players to use technology to challenge line calls they think are incorrect.
The technology being used by the Hawk-Eye system is Video Analysis. Here is how it works.
Multiple cameras are placed around the court and players. These cameras are usually placed high up, so that there is less chance that a player will be blocking the ball from the camera view.
Multiple cameras are used to ensure accuracy of tracking the ball and to account for possible occlusion (the ball being hidden from the camera view by the players body...)
The system uses at least 4 high speed video cameras, with a capture rate presumed to be 500 frames per second.
The camera position is calibrated to determine its position in space and relative to the other cameras in the system. The lines on the court are also used in calibration and to compensate for any camera movement.
The center of the ball is tracked in 2D by each camera. The ball therefore is like a reflective marker or point on the body. Using the information from all the cameras, the Hawk-Eye system then triangulates the 3D position of the ball.
This process is done for each captured frame so that a trajectory of the ball can be created and then overlayed on an animated background containing the lines of the tennis court.
Finally the skid and compression of the ball is measured by examining the position and trajectory of the ball prior to the bounce and its position and trajectory after the bounce. In this way they can determine how long the ball was on the ground and how it skidded over the ground.
The Hawk-Eye system is said to have an accuracy of 3.6 mm.
I believe that the use of video technology in this way is great for the sport of tennis and for the players piece of mind as well as spectator enjoyment. However we have seen a number of controversial calls with the Hawk-Eye system. Take a look at video of 2 big ones here.
In this first video we see a very tight call for Mikhail Youzhny over Rafael Nadal at Dubai in 2007.
In both cases we would have to say that the ball likely looked out to the lines judge who made the call. In both cases the player is most likely only challenging the call because it is a crucial point (Yozhny vs Nadal - Set Point, Nadal vs Federer - Break point). The Hawk-Eye system suggests that in both cases these calls were measured as being 1mm IN, meaning the ball was 1mm from being out. Could Hawk-Eye have been wrong in either or both of these calls and what does it mean that it is 2-3 mm accurate but can suggest that the ball was in by only 1mm? Here are some points that may effect the accuracy of the system.
The camera capture rate of 500 frames per second may be too slow for the hard hitting tennis game of today. Andy Roddick has recorded a fastest serve at 155 mph and ground strokes are often hit with a similar speed. Assuming a capture speed of 500 frames per second or 1 frame every 0.002 seconds, the ball will have moved about 139 mm for every video frame. This may not be sufficient data to determine the position of the ball to within 1 mm.
The more cameras that are used the better the chance of tracking the ball and the higher the accuracy. However there are possibilities of occlusion by players, tennis rackets and the net, which will lead to reduced accuracy.
High speed video capture also needs excellent lighting. We have discussed the importance of lighting for high speed capture in a previous post . Therefore the system will work best under a roof with artificial bright lighting and will possibly have a problem tracking the ball outdoors, particularly when there is cloud cover or as it gets later into the evening.
Assuming everything is perfect for capture, the center of the ball has to be identified as accurately as possible too. If a camera sees the ball at a funny angle or partly occluded the center may not be correctly defined by this one camera and the position of the ball will be inaccurate.
The skid and compression of the ball is being estimated and extrapolated based on the trajectory of the ball before and after the bounce. Any inaccuracies in tracking the position and flight of the ball will become larger during an extrapolation (estimation of the movement).
The Hawk-Eye system may not be perfect but it is definitely a step up from the eyeball view of a line judge, particularly when the ball is moving at high speed. We believe Hawk-Eye has improved the line calls in Tennis and this is great for the players and spectators alike. However it still leaves room to debate exciting points and close matches. Enjoy the US Open Tennis and hopefully we will not see any controversial Hawk-Eye calls.
About the Author
Dudley Tabakin is Co-Founder of Sadaka, LLC http://videosportsanalysis.blogspot.com, a motion capture and biomechanics consultancy. Clients include FootJoy, Titleist, Warrior Hockey, Vicon Motion Systems, Innovision Systems Inc. and other Sports and Motion capture and biomechanics software companies
