Recreational tennis resumes - elfin safety

wimdledont · Challenger level

Recreational tennis resumes - elfin safety

wimdledont · Challenger level

Footnote 1

In support of my thesis, I cite the famous observation of Emeritus Professor of Tennis, Doctor Mcenroe, JP, in his seminal work of 1979,which argued that the impact of a tennis ball upon a static deposit of calcium carbonate would cause the spread of calcium carbonate into the surrounding air.

"Chalkdust, dammit. I saw chalkdust." Mcenroe, JP, University of Flushing Meadow, 1979.

JonH comes home · Tennis legend

wimdledont wrote:
Footnote 1

In support of my thesis, I cite the famous observation of Emeritus Professor of Tennis, Doctor Mcenroe, JP, in his seminal work of 1979,which argued that the impact of a tennis ball upon a static deposit of calcium carbonate would cause the spread of calcium carbonate into the surrounding air.
"Chalkdust, dammit. I saw chalkdust." Mcenroe, JP, University of Flushing Meadow, 1979.

1981 I think that paper was written. Good paper though. Chalk mistaken for paint though, which doesnt spread so much and thus impacts the validity of any findings based on this thesis.

wimdledont · Challenger level

Yes, sorry about the year. IIRC this was a draft of a paper, which failed to pass peer review, and was rejected in the refereeing process, anyway. But it does have some relevence to the issue of airbourne debris after the impact of a tennis ball.

JonH comes home · Tennis legend

wimdledont wrote:
Yes, sorry about the year. IIRC this was a draft of a paper, which failed to pass peer review, and was rejected in the refereeing process, anyway. But it does have some relevence to the issue of airbourne debris after the impact of a tennis ball.

I think McEnroe's earlier work which was in 1979, based on the findings of his match against Nastase in New York is also worth a look. Shaking the umpires chair and the impact of that on spread by Mr Nastase, the Romanian professor, is worthy of further investigation and analysis. Sadly Nastase was kicked out of the University for his bad behaviour and no further research was available

wimdledont · Challenger level

Thinking it through here, as I type more nonsense...

If you think about it, the outer covering of a tennis ball is basically a piece of towel, or flannel. As a heavily respiring and perspiriing player touches any ball, it could quickly pick up quite a heavy load of virus, particularly, if they coughed into their hand, or indeed put a hand - even a gloved hand - near their face. With some players' little tics and mannerisms, I'm sure that can happen half a dozen times per point played. The virus would pass from mouth, to glove, to ball.

Then start banging this infected flannel, wrapped around a rubber ball around the place, and banging it violently into hard objects, and releasing a - lets be conservative - cloud of infection with a 2 metre radius with each impact...

I reckon you'd have infected everybody in quite a large indoor sports hall fairly rapidly. Possibly with such a tiny dose that it merely acted as a tiny vaccination, led to an extremely mild infection, and proved a great blessing to all concerned. But I have absolutely no idea.

Spireman · Club Coach

I think we have to accept some risk in life. The phrase 'until it is safe to....' is infuriating as there is risk in everything we do (or don't do).I would like to think those with symptoms of a cough or sneeze are not rushing out to play tennis, but the main point is that a tennis court is, I think, 78ft long, so even with one player at the net there is about 35 ft between them (both players could be at net but much rarer). If a player has transferred virus into the ball the majority of it will disperse at their end of the court. When a tennis ball is wet we see the droplets come off as soon as it is hit. I just don't think the risk is very high for a player at the other end. Of course don't play if you are unwell, or in high risk groups at the moment. But at this stage the benefits of getting out and playing outdoors, with some safeguards in place, seem to far outweigh what is probably a very slight risk.

wimdledont · Challenger level

Imagine I dropped a tennis ball in water, then served it. It would produce a cloud of water as I served it, it would also spray another one (in my case) half way between the service line and the base line. It woulkd not arrive 78 feet away as a bone dry tennis ball, and as my opponent contemptuously knocked it back into the fence behind me, there would be another release of spray, within a metre or so of their body. I'd expect them to get a bit wet.

All in all, I think that if an infected person and a non-infected one play a set of tennis together, the chance of infection NOT being transmitted from one to the other is tiny. French kiss.ing would be a more certain method, granted.

Spireman · Club Coach

I can't agree with that. The analogy of a soaking wet ball can't be right...I agree that particular ball will take quite a few shots before it stops spraying many water particles when it is hit. I think a ball with virus on will have many fewer particles on it to lose than the soaking wet ball. Any left to be lost when hit at the supposed non infected players end will be few in number and will go in the air randomly around the ball and be further dispersed in the air outside. Remember that no one is talking about playing indoors yet. There is always a theoretical risk in outdoor tennis, I just think it is minimal and worth taking for most people bearing in mind the benefits of tennis, both mental and physical. (And taking into account many of those infected are asymptomatic or get very mild symptoms anyway).

wimdledont · Challenger level

The other, much more obvious means of transmission would come from both players touching the same ball, then each one touching their own face. I do think the risk of trasmissionis very high between the two players. Its like two people tossing an infected flannel between each other. Outside, the danger of infecting those nearby may be less, but I think that a part of your argument comes down to saying "it doesnt matter if the disease is spread or not, because its not serious."

I think it is serious, and serious mistakes were made in the decision making process before our late imposition of a lockdown, based on decisions taken on what Boris refers to as Brit common sense, and a disregard for scientific evidence and advice. The day that he was bluffly boasting that he was merrily shaking hands, SAGE were recommending that people stop shaking hands.

I strongly suspect that the resumption of recreational tennis has been made with a similar degree of bluffery, lack of homewrok and investigation into the actual risks, and just gut instinct, and perhaps some cajoling from the chaps down at the club.

Spireman · Club Coach

The rules for resumption are that each player has their own tennis balls, initialled, which they use for serving. Their opponent uses their own balls on their service games. Balls are returned to their 'owner' by kicking them or hitting without touching them with hands. So two players should never be touching the same ball at all. Playing tennis is not playing catch with a wet flannel....obviously.
I am not saying at all that it doesn't matter if anyone catches what I can see can be a very nasty disease, just that the risk from playing tennis with these rules is very low in my opinion. A study came out today of testing 11000 people randomly (asymptomatic, randomly selected people) and 1 in 400 had the virus. I don't want to comment on the politics of it all but we all do need things to look forward to which we enjoy doing, IF we judge the risk is low enough to be worth taking, which I definitely do.

Elegant Point · Satellite level

Unfortunately no scientific data on this one, but there are a number of articles pertaining to other sports and the same key concepts of infectious dose and transmission should apply.

The formula to remember is: Successful infection = Exposure to the virus X time.

Assuming all tennis is played outdoors, how easy is it for the virus to travel through the air and how many virus particles would you have to inhale to start an infection? University of Birmingham estimates high hundreds to low thousands of live virus particles to start an infection.

In China, a recent study suggests C-19 transmission is much more likely to happen indoors, out of 318 cases, 1 was from outdoor transmission. Outdoors, wind, sunlight, humidity etc will all affect virus transmission and survival.

If you have a set of marked balls, only serve with your balls and don't handle your opponents balls (flick them back with your racket) in IMO the risk of contracting C-19 playing tennis outside with 1 other symptom free person is likey fairly low. You and your opponent could also wear a mask?? I think the benefits to mental health and wellbeing greatly outweigh the risks and I was out on court this morning biggrin

The Realist · Junior player

My daughter has resumed coaching today.

For one to one coaching, only she is allowed to touch the tennis balls, so in theory no serving practice ( although perhaps could be allowed if player is wearing gloves?); she is giving a lesson to a seven year old today , so the no ball touching could prove difficult. although parent will be present; she is only allowed to use eight tennis balls, so no basket drills either.

wimdledont · Challenger level

Thanks to HIGNFY...

www.youtube.com/watch

Elegant Point · Satellite level

Realise we are very lucky to have courts to play on, but confounded by LTA logic:

How is it OK for 2 people from different households to play singles, a family of 4 can play doubles (so nothing to do with density of players on court), but 2 families from 2 different households can't play doubles (ie pair A from same household and pair B from same household, but different household to pair A) ?

How is the risk prohibitive for inter-household doubles, but not for inter-household singles, if players are symptom free, only serve with their own balls, don't swap ends and don't touch the oppositions balls? I have friends who are experts in Virology and no one can provide a satisfactory answer.

Any mathematicians, risk analysts, or anyone who has an opinion? I feel an email to the LTA maybe required? or maybe I can get Joe Lycette to look into it ;0)