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Ice tennis

Res publica   21.07.23  

Rob Worling ama spingere gli sport invernali oltre i limiti.
A lui non basta giocare solo a hockey in inverno e a tennis in estate. Ecco perché ha combinato questi due sport per crea un campo da tennis su una pista di ghiaccio.
L'ice tennis sembra davvero divertente e competitivo, almeno al pari degli altri sport di Worling: il calcio su ghiaccio, l'ice football e il basket su ghiaccio.

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La fisica dei campi da tennis

Res publica   04.07.15  

Esistono oltre 160 superfici diverse su cui giocare a tennis.
Grantland ha raccolto le analisi su come queste superfici possono influire sul gioco.

The most important factor is the "coefficient of friction," a measurement of the abrasive force between the ground and the tennis ball. Courts with high frictional coefficients interfere with the movement of the ball, disrupting its forward momentum. Think of a sluggish clay court. According to experiments performed by the ITF, a shot hit without spin and traveling at 67 mph will lose about 43 percent of its ground speed after contact with the clay surface, slowing down to a leisurely 38 mph. (The reason clay steals momentum is rooted in the friction of all that loose brick, which clumps around the ball. Each clump is like a little speed bump.) As a result, players have a few extra milliseconds to hit a return.

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Tennis in slow motion

Res publica   02.07.15  

Un servizio a oltre 228 km/h ripreso in super slow motion a 6.000 fps. Niente di meglio prima di godersi una nuova giornata a Wimbledon.

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Il doping nel tennis

Res publica   09.07.13  

A differenza dei controlli serrati nel ciclismo la cultura antidoping nel tennis è ancora una barzelletta.

Here's how it currently works. Players take part in two types of tests: in-competition tests during Grand Slams (reportedly after losing a match) and completely unannounced out-of-competition (OC) tests. Traditionally, the sport has relied on urine tests for both cases, which are an easy way to spot steroids. Blood tests, which detect human growth hormone (HGH, or what made some baseball players monstrous) and certain types of the more sophisticated blood doping, are more expensive and expire more quickly.

Miller [the executive director of the ITF’s science and technical department, n.d.r.] says his organization should be doing more OC testing, and that there is especially a case for increasing OC blood tests, which are probably the most effective way to catch a doping player. In 2012, tennis conducted 2,185 tests--only 63 of which were OC blood tests. That's a small number, though more than the 21 done in 2011. (For comparison, cycling conducted 13,745 tests in 2011, 3,314 of which OC blood tests.) This year, tennis also adopted the biological passport, proven to be effective in cycling. These digital documents track a player’s blood profile, meaning they can detect changes in biological markers over time. The drug might be washed out of your system, but science says something fishy’s going on. Unfortunately, the passports need a few years of player data to really be effective.

A major problem with the OC tests, in any case, is that they're regarded by many as a joke. In 2011, Serena Williams locked herself in her Los Angeles home's panic room when she thought an intruder was lurking outside. It was a drug tester; ITF data shows Williams didn’t take an OC test at all in 2010 or 2011.

In 2012, Djokovic, Murray, and Federer each had around seven in-competition tests and up to three OC tests--it's unclear whether these were urine or blood tests. When it comes to OC testing, an injury to a top player like Nadal is probably reason enough for specific "targeting," and would explain his unusually high seven-plus OC tests (PDF) in 2012.

Another common complaint is that if a player tests positive, his or her name isn't revealed right away--or possibly at all. Only after a tribunal has determined guilt, usually within six months, is a suspension revealed, which means that players can fail a drug test without fans ever finding out. This closed system undoubtedly fuels many of the juiciest doping suspicions; some tennis watchers suspect that Nadal's seven-month absence from the professional circuit between July 2012 to February 2013, and his loss at the 2009 French Open and withdrawal from Wimbledon that year, may actually have been a "silent doping ban" that was never publicly disclosed.

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