14D.4 Ball NEW DISCUSSION
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Started
14D.4 Ball
A “dead” tennis ball that reaches 30 percent to 50 percent of its original height after bouncing onto concrete is used.
The international tennis federation rules say that a tennis ball should bounce 135-147cm when dropped from 254cm. Instructions for method of dropping here
Instead of "30 to 50 percent" why don't we just change it to an actual measurement. 41-74cm when dropped from 254cm. This gives an actual measurement that can be used.
30% of 135 = 40.5
50% of 147 = 73.5
Rounded to nearest whole number = 41-74cm
Comment
What is the advantage of such a rule modification? It is probably easier to decide if the ball reaches 50% of the original height instead of a certain height in cm.
I mean, you can drop the ball from 2m and estimate if it reaches more than 1m. Seems to be easy for me...
and why do you calculate 30% of 135 and not of 254?
Comment
1. Why do we have a rule at all if it isn't measurable.
The rule says the ball used must bounce 30-50% of the original height of bounce. Who knows what the original height of a tennis ball is? Is the tennis ball an official tennis ball or one of those cheap ones you buy from the store to give to your dog, because those bounce much lower. Is the 30-50% of original height dependent on whether you get one of these dog balls or an official tennis ball? Is 30-50% of a dog ball considered acceptable even though 30-50% of a quality tennis ball is a different height.
If you are using the same tennis ball for 3 years and it bounces less and less over time will you remember in 3 years time what the original bounce height was so you know if your ball is within 30-50% as the rules state?
Why have this rule at all if it is unmeasurable. Putting an actual height in is an easy way to objectively measure if the ball is within the supposed rule, otherwise why do we have the rule at all?
2. Why did I calculate 30% of 135 and not of 254?
The IUF Hockey rule states that the ball should bounce 30-50% of its ORIGINAL bounce. The original bounce is how high it bounces after being dropped when new. We know from the tennis rules that a tennis ball that is dropped from 254cm will bounce 135-147cm. Therefore to work out what 30-50% of original bounce is we need to work out 30-50% of 135-147cm.
The original bounce of a tennis ball is not 254cm it is 135-147cm.
Honestly I think it makes more sense to take out the entire rule, why do we need to play with a "dead" tennis ball. But if we are going to have a rule in the rulebook why do we have one that is not possible to even measure.
Comment
That's interesting. I understand the original height as the height where you release the ball.
And yes it is difficult to measure. Therefore, I also suggest to delete the part "dead". It is not necessary to play with a "dead" ball. A normal new tennis ball reaches 53% to 58% (considering your height-values). For me that is okay and not a big change.
(anyway we play with new tennis balls in Switzerland and renew the balls for each season to ensure having the same conditions)
Comment
Interesting. In contrast to Steven, I always interpreted the "original
height" as the height from which the ball was dropped, not the height
that a new tennis ball would reach after bouncing. According to the
tennis rules, a new tennis ball reaches between 53 % and 58 % of the
original height. A ball suitable for unicycle hockey bounces a bit less:
between 30 % and 50 %.
If anyone has a good idea how to describe a "dead tennis ball" in a
qualitative (non-quantitative) way without using the numbers 30 and 50,
maybe we can simplify the current rule.
Comment
Ah, I just see that Christian already posted something similar...
Comment
I too think that original height means the height you drop it from. If we want to get rid of 30 and 50 percent all we need to do is say when dropped from 100cm it must bounce back 30-50cm.
Comment
I do not play tennis and I didn't know what their rules to a tennis ball have to be. So far I understood that we should use for hockey used tennis balls. The simple check as a referee I did how Jamey said. Take the ball to 1m let them drop and if they bounce between 30 and 50 cm they are good to play for hockey (and this was for me a so called "dead" tennis ball.)
In practice we buy new balls, use them for training and sort out balls to use in the next tournament.
What do you think about:
"A tennis ball that bounce onto concrete 1/3 to 1/2 of the hight it was dropped, should be used for hockey."
(This would eliminate the word "dead", real "dead" balls less than 30 % and brand new ball with more than 50 % bounce.)
Comment
I think the issue here appears to be the wording.
A “dead” tennis ball that reaches 30 percent to 50 percent of its original height after bouncing onto concrete is used.
I have always associated a "dead" tennis ball as one which has lost its bounce. So when the ruling said "original height" I assumed that meant the height it originally bounced when it was not dead.
Perhaps a rewording could make it more clear? Or remove the requirement of a dead tennis ball. Is there any real need for a dead tennis ball?
Comment
If it is thought to be important that we use a "dead" tennis ball, I asked a few from Australia, one suggested the wording.
A tennis ball that when dropped on concrete rebounds 30-50% of the height from which it was dropped, should be used.
Perhaps this is more clear? Could still be improved.
Comment
Sounds pretty good. However, you use "should" for both the tennis ball
as well as for the bouncing. I think we need to make clear that the type
of ball _must_ be a tennis ball:
"A tennis ball is used that, when dropped on concrete should rebound
30-50 % of the height from which it was dropped."
Here I use the phrase "IS used" for the type of ball but "SHOULD
rebound" for the bouncing description. A ball that bounces 29 or 51 % is
still okay for me but a non-tennis ball is not.
Comment
All got the sense, my English is not good enough. I will agree what is coming up.
Comment
"A tennis ball is used that, when dropped on concrete should rebound
30-50 percent of the height from which it was dropped."
That is clear enough for me
Comment
I can agree with the new wording. But as Steven asked: Is there any real need for a dead tennis ball?
I think not. The difference between a ball which reaches 50% and one which reaches 30% is large. These two balls behave in totally different ways. If in a match different balls are used it can be that players have to convert their expectations how the ball rebounds several times during the match. If we play only with new balls the difference between the balls would be smaller.
Comment
I prefer a 30% ball vs a brand new ball. I would be more for changing the rule to 30-40% than to changing it to a new ball.
Comment
It is more difficult to always have a tennis ball which reaches 30% than to take a new ball.....
I suggest to follow Nicolai's proposal or (if this is not supported from a majority) to follow Steven's proposal.
Comment
Also a NEW tennis ball bounces 54-57% of its height. Not hugely different from 50% making it less useful having the dead ball rule.
A NEW tennis ball falls to under 53% in 10 games (not MATCHES) of tennis. Loss of bounce which is why in professional tennis they get changed every 9 games.
With a ball reducing its bounce fairly quickly I feel the "dead" ball rule is fairly redundant.
Comment
I see three possibilities now:
1) If we only want to improve the wording without changing the meaning,
I think we can agree on the following text:
"A tennis ball is used that, when dropped on concrete should rebound
30-50 percent of the height from which it was dropped."
2) If we want to remove the requirement of the 30-50 percent bounce, the
text would be very short:
"A tennis ball is used."
3) If we want to enforce a new ball, the text would be:
"A new tennis ball is used that, when dropped on concrete should
rebound 53 to 58 percent of the height from which it was dropped."
For me options 1 and 2 are okay but I don't think enforcing new balls as
in option 3 is a good idea.
Comment
I don't think enforcing new ball is a good idea.
I believe number 2 "A tennis ball is used" is best for a number of reasons.
- Everyone is using the same ball
- A new ball bounces only slightly above our current allowable level
- Balls lose their bounce fairly quickly through play and will reach the traditional "dead" level quickly
- There is no safety benefit of having a ~10cm lower bounce
- It makes it easier to enforce the rule
- I have never seen someone seriously enforce the current rule they have only done it by eye which doesnt differentiate between 50% of bounce and 54% of bounce so the current rule is redundant.
- If we only had a new ball that bounces 54% not 50% I think both teams would agree to play with it.
Comment
It looks like that nearly al kind of tennis ball should be allowed to to play with. We do not like "real dead" balls. I like to bring in 4).
4) "A tennis ball is used that, when dropped on concrete must rebound not less than 30 percent of the height from which it was dropped."
Comment
Has that ever happened Herbert?
I played tennis for 8 years and have played hockey for 3. Apart from a broken ball i.e. one with a split in the rubber I don't think I have ever seen a ball bounce that little.
From everyone's experience has any league had to throw out a ball because it was bouncing less than 30%? I think we have had broken balls but never one that was functional.
Comment
Yes I have seen. On a tournament the host had some cheap dog balls (looked like tennis balls) provided, these balls were not broken but nearly "dead". When we say ..."bouncing less than 30% .. ." this would covers all kinds of dead or broken balls and would allow to play with all other tennis balls I do not care how many percentage they like to rebound.
Comment
To be sure no too dead ball or no broken ball is used I would take suggestion 4 from Herbert.
Comment
I also support Herbert's option 4) with the minimum bounce:
"A tennis ball is used that, when dropped on concrete must rebound not
less than 30 percent of the height from which it was dropped."
Comment
agree
Comment
Steven, the sentence that you put into the proposal doesn't contain
"concrete" as the surface anymore. I thought all we wanted to change is
to remove the word "dead" and remove the 50% upper limit. Wouldn't the
following be sufficient?
OLD:
A "dead" tennis ball that reaches 30 percent to 50 percent of its
original height after bouncing onto concrete is used.
NEW:
A tennis ball that reaches more than 30 percent of its original height
after bouncing onto concrete is used.
Comment
Using the words "original height" doesnt cover the original confusion of what "original height" means. I will try and word something that fixes this but has concrete in it.
Comment
Looks fine to me now.
A minor question for the native speakers: Is
"30 percent of the height of which it was dropped"
or
"30 percent of the height from which it was dropped"
better?
Comment
Rolf:
"30 percent of the height from which it was dropped"
is correct.
Comment
Thanks! I revised the proposal accordingly.