Saying indoor courts are faster is actually due to the SURFACE or the ATMOSPHERE?

d-quik

Hall of Fame
Given that indoor courts are generally cooler, shouldn't it be slower than outdoors? I thought hotter = faster.

If it is the surface (outdoor erosion makes the surface grittier, thus slower) then would it be right to say that if both courts were laid down BRAND NEW WITHOUT EROSION it would play in the same speed indoor and outdoor?
 
D

Deleted member 54265

Guest
Should be obvious that wind is the most important factor. Wind can come from all kind of directionsand and is generally making the play slower. It can be hard to take real advantage of tailwind, you often also slow down in order not to hit long.

Indoor you have no wind (or very little) and can be more confident in your strokes and thus hit faster.

This is just my opinion, and there may be other factors too.

Cheers, Toby
 

FiReFTW

Legend
Yes @Toby14 is right.

OP dont be ignorant.

Its obvious indoor will be generally faster and consistently so.

Outdoors wind comes from different directions sideways frontways and makes the ball slower most of the time, only when the wind is behind you is it potentially faster, but that doesnt happen that often.

Thats why sometimes outdoors it can feel very fast while sometimes very slow.

But indoors it always is how it is because wind has no effect.
 

pencilcheck

Hall of Fame
I sort of agree with OP assessment

I think based on my experience I always feel the ball is more spiny and floaty and slower during hot day outdoor, and it feel faster when there is wind (depending on the wind direction that it is blowing but it adds more energy to the court)

But the ball compare to indoor is slower probably also due to court outside has gone through rain, sun and other factor that erode whatever the surface had to be more smooth and therefore it bounces less high and also not able to transfer that energy into the shot so I am guessing outdoor courts absorb a lot of the ball energy so the receiver will feel slower

indoor doesn’t have those issue, no wind no surface errotion so it has consistent response.
 

MaxTennis

Professional
I sort of agree with OP assessment

I think based on my experience I always feel the ball is more spiny and floaty and slower during hot day outdoor, and it feel faster when there is wind (depending on the wind direction that it is blowing but it adds more energy to the court)

But the ball compare to indoor is slower probably also due to court outside has gone through rain, sun and other factor that erode whatever the surface had to be more smooth and therefore it bounces less high and also not able to transfer that energy into the shot so I am guessing outdoor courts absorb a lot of the ball energy so the receiver will feel slower

indoor doesn’t have those issue, no wind no surface errotion so it has consistent response.

This is why I love playing at Bay Club SF! The conditions suit my game really well :)
 
D

Deleted member 54265

Guest
I sort of agree with OP assessment

I think based on my experience I always feel the ball is more spiny and floaty and slower during hot day outdoor, and it feel faster when there is wind (depending on the wind direction that it is blowing but it adds more energy to the court)

But the ball compare to indoor is slower probably also due to court outside has gone through rain, sun and other factor that erode whatever the surface had to be more smooth and therefore it bounces less high and also not able to transfer that energy into the shot so I am guessing outdoor courts absorb a lot of the ball energy so the receiver will feel slower

indoor doesn’t have those issue, no wind no surface errotion so it has consistent response.

I head some commentators state that when they close the roof at the US Open, the court becomes faster and that favors Federer.

So I guess same surface, about same temperature and humidity.

Biggest change in condition, in one word:

Wind

:)
 

d-quik

Hall of Fame
OP dont be ignorant.

Its obvious indoor will be generally faster and consistently so.

Thats why sometimes outdoors it can feel very fast while sometimes very slow.
completely contradicts what pros say
And there are numerous interviews where players complain about the roof slowing down the ball on other courts
yeah pretty OBVIOUS i am not the ignorant one here bud. Nice try though
 
D

Deleted member 54265

Guest
Federer prefers closed roof - He always excels, and plays better on fast courts. But commentators could be wrong about the courts getting faster with the roof closed.

About AO

post match interview with rafa had a question on the roof

Q. Does having the roof closed or opened, the way it changes the way the court plays, is that good for your game or bad for your game?

RAFAEL NADAL: Well, in the end you have to play well in both situations, no? Change a little bit, but not too much. Maybe is a little bit faster with the roof. But that's it.
 

d-quik

Hall of Fame
I head some commentators state that when they close the roof at the US Open, the court becomes faster and that favors Federer.
source? Because the posts that stating players say otherwise is completely discrediting you.
 
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Deleted member 54265

Guest
Its complicated with a lot of contradictions, mostly when you close a roof at the AO or Wimbledon, humidity will rise because of 15.000 Spectators and that can slow the ball down as it gets heavier, this is not the same as the court slows down. But I guess it can be looked at both ways.

My personal experience (and not playing for 15.000 spectators) is that indoor courts are faster with a good margin compared to outside courts, but I also live in a region where indoor courts generally are warmer than outside courts.

You can lyfao, I really don't care, and I am done with this.
 
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d-quik

Hall of Fame
Get a life man.
lmfao... resorting to name calling when proven wrong. I am not the one who has life problems. Sorry that trying to uncover truths about the game we are all enthusiastic is considered not having a life... some people really cant handle getting called out

Please find more credible sources than just another tt poster. Even then it is one player (nadal) disagreeing with many others.

Smh
 
D

Deleted member 54265

Guest
Indoor is easy mode imo, no sun to bother you on the serve, overhead, no glare, no need to squint your vision, no wind to mess with timing, footwork those extra milliseconds and confidence makes everything faster.

I agree, the game is faster on indoor courts. Perhaps the actual surface is the same as outdoor, but you play faster on indoor.

In extreme situations like at AO or Wimbledon, the 15.000 spectators will change the humidity and air inside when the roof is closed, making the ball slower, and that can make the game slower than on the outside courts.
 

zipplock

Hall of Fame
I've always felt I doors plays faster primarily because of the lighting. I know the conditions are stable because of closed environment, etc., but something about the lighting always messes with me. Harder for me to visually track the ball as quickly as when playing in sunlight.
 

Dou

Semi-Pro
mostly it's the surface - just put less sand in the paint. there is no sun and no wind, so the players can handle fast balls... also due to limited court time in many situations you don't want an indoor match turn into a slow clay type of grind where you can't finish a match in 1.5 hours.

when the roofs are closed the ball should travel a bit slower due to increased humidity.

Federer prefers indoor because his game is more precise than the others say Rafa and Nole... he has a clear advantage in putting the serve in the corners precisely, if there is no wind.... once conditions get tough and both players have to aim more to the middle and the match turns into a more physical grind then Rafa/Nole has advantage over Fed.
 

Rosstour

G.O.A.T.
Wind is just one variable. If we are not discussing humidity and air pressure then we are just scratching the surface.

Then there is the surface itself. We have great public courts in my town and they play vastly differently. My buddy and I call them Australian Open vs US Open, the slower courts are a real slog, even more taxing and grinding than the two har-tru facilities we have

Federer prefers closed roof - He always excels, and plays better on fast courts. But commentators could be wrong about the courts getting faster with the roof closed.

About AO

I've always felt I doors plays faster primarily because of the lighting. I know the conditions are stable because of closed environment, etc., but something about the lighting always messes with me. Harder for me to visually track the ball as quickly as when playing in sunlight.

This is another thing I thought of, combine lower humidity and air pressure and the ball is already faster, then try targeting it under entirely artificial light...favors a player with a great serve IMO.
 

tlm

G.O.A.T.
If surfaces are the same then indoors is faster, but I don’t agree that it’s all about the wind. You can play outside when there is no wind and it’s still slower than indoors. The ball sits up more outdoors but indoors it shoots through the court lower.

The sun can speed it up outdoors and when hot it can definitely make the ball bounce higher outside, also the humidity can affect play. If you get a really clear day with low humidity then it can get faster outdoors, plus I’ve noticed a big difference if I play at midday with the sun out and in 80’s compared to playing in the evening without the sun.
 

ptuanminh

Hall of Fame
The surface definitely matters too. The indoor court i play at is made of this hard rubbery kind of material, feel good on the knees, but it bounces super fast. Most points are over in 3 4 shots.
 

Kevo

Legend
Discounting the wind, indoor courts and outdoor courts are not necessarily different from one another when talking about hard courts. It just depends on how the court was built and surfaced. I've played slow indoor courts and fast outdoor courts. Around here, most of the indoor courts are the same surface treatment as the outdoor courts and there isn't much to notice at all. There are a couple of places that have fast indoor courts and it's almost funny how much faster they are. You pretty much have to adopt a different style of play when you compete on them. But courts that fast are rare around here.
 

pencilcheck

Hall of Fame
I head some commentators state that when they close the roof at the US Open, the court becomes faster and that favors Federer.

So I guess same surface, about same temperature and humidity.

Biggest change in condition, in one word:

Wind

:)
Interesting that you conclude this way. I actually is trying to make the point that court surface affect the speed more. Temperature also as well now I am thinking about it
 

tlm

G.O.A.T.
Discounting the wind, indoor courts and outdoor courts are not necessarily different from one another when talking about hard courts. It just depends on how the court was built and surfaced. I've played slow indoor courts and fast outdoor courts. Around here, most of the indoor courts are the same surface treatment as the outdoor courts and there isn't much to notice at all. There are a couple of places that have fast indoor courts and it's almost funny how much faster they are. You pretty much have to adopt a different style of play when you compete on them. But courts that fast are rare around here.

I don’t agree and either do any of the guys I play with. If the surface is the same then it’s always faster indoors, I’ve rarely played indoors in the summer but if it’s super humid then it may be closer to outside but I think it would still be faster. Playing in the winter indoors it’s usually pretty dry inside so between that and perfect conditions it’s definitely faster than outdoors.
 

jm1980

Talk Tennis Guru
Whenever these topics come up, people start coming up with physically unsound theories o_O

Given that indoor courts are generally cooler, shouldn't it be slower than outdoors? I thought hotter = faster.

If it is the surface (outdoor erosion makes the surface grittier, thus slower) then would it be right to say that if both courts were laid down BRAND NEW WITHOUT EROSION it would play in the same speed indoor and outdoor?
Hotter is not faster. Hotter conditions are more physically demanding for the players, and it also makes the ball bounce higher (which slows down play)

Erosion doesn't make the surface grittier. On the contrary, it removes the grit from the surface... At least initially. But if the court falls into a state of disrepair and the paint starts to chip off and stuff, then yes, it does become grittier. But at that point it's not really a tennis court anymore
Yes @Toby14 is right.
Outdoors wind comes from different directions sideways frontways and makes the ball slower most of the time, only when the wind is behind you is it potentially faster, but that doesnt happen that often.
If you are playing with the wind is behind you then your opponent is going to be playing against the wind, and vice versa. In theory, any wind blowing from baseline to baseline should have no net effect on the speed of the ball in flight.

The same applies to wind blowing from side to side: if it adds speed to a ball hit CC from deuce to deuce, then it slows down balls going CC from ad to ad. Unless all your rallies are against the side wind, there should also be a negligible effect.

But the ball compare to indoor is slower probably also due to court outside has gone through rain, sun and other factor that erode whatever the surface had to be more smooth and therefore it bounces less high and also not able to transfer that energy into the shot so I am guessing outdoor courts absorb a lot of the ball energy so the receiver will feel slower

indoor doesn’t have those issue, no wind no surface errotion so it has consistent response.
Why on earth would a smoother surface be slower?! Try rolling a ball on a smooth surface vs on a rough one, and see which one goes faster.

Also generally speaking, the lower the bounce, the faster the court. A higher bounce gives you more time to get to the ball before it bounces twice.

Saying indoor conditions are slower than outdoors contradicts pretty much every experience we've heard from players.

An uncited reddit post is not going to change that.
I agree, the game is faster on indoor courts. Perhaps the actual surface is the same as outdoor, but you play faster on indoor.

In extreme situations like at AO or Wimbledon, the 15.000 spectators will change the humidity and air inside when the roof is closed, making the ball slower, and that can make the game slower than on the outside courts.
Why would humidity make the ball "slower"? Adding moisture to the air makes it less dense, so in theory, the ball would travel faster through more humid air.

It's also not even established whether closing the roof rises or drops the humidity. An indoor environment can also have the humidity carefully controlled and adjusted to be higher, lower, or the same as the outdoor humidity
Wind is just one variable. If we are not discussing humidity and air pressure then we are just scratching the surface.

This is another thing I thought of, combine lower humidity and air pressure and the ball is already faster, then try targeting it under entirely artificial light...favors a player with a great serve IMO.
Air pressure changes due to a roof are negligible to nonexistent. For humidity, see above.
 
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jm1980

Talk Tennis Guru
The reasons for any perceived change in speed are mostly due to the human factor. The short version is, with the wind variable removed, players can simply take bigger cuts at the ball. It's also generally cooler indoors, which makes usually results in faster play.

Changes in temperature and humidity also affect the players more than the flight or bounce of the ball. Hotter conditions generally make the ball bounce higher (slowing down play). Humidity doesn't affect the ball in flight a whole lot. Note that more humidity in the air makes it less dense, which should make the ball travel faster in flight.

But the biggest factor when temperature and humidity increase is the human factor. The hotter and more humid it gets, the quicker the human body will tire out, which is why hot and humid conditions "feel" slow. It's your body is slowing down - not the ball. So does closing the roof increase or decrease temperature and humidity? Well, that depends on how good the HVAC system is. But temperatures generally get cooler indoors and this makes it both more comfortable to play in, and it also makes the bounce lower.

Surface shouldn't matter much, since the surface can be adjusted regardless of whether the tournament is indoors or outdoors (and this is specially true in pro tournaments),
 

Kevo

Legend
I don’t agree and either do any of the guys I play with. If the surface is the same then it’s always faster indoors, I’ve rarely played indoors in the summer but if it’s super humid then it may be closer to outside but I think it would still be faster. Playing in the winter indoors it’s usually pretty dry inside so between that and perfect conditions it’s definitely faster than outdoors.

I should have said discounting weather conditions. But the large speed difference in indoor vs outdoor surfaces in my experience is actually due to the surface. It can make a substantial difference. I've occasionally been able to hit on outdoor courts that were resurfaced just after they finished and sometimes you can notice quite a change with those too. Around here there was a period of time when all the courts were switching to the ATP blue surface. Many of the courts that played differently started playing very much the same after the surfacing.

All I'm saying is that at most of the clubs around here, with a few exceptions, going from outside to inside is different only in the sense that it's cooler, the lighting is worse, and there's no wind. The play on the courts themselves is the same because the surface is the same. There is one club in particular that is close to us where going from indoor to outdoor is a whole different experience though. The surface of the courts are clearly different.
 

Kevo

Legend
Surface shouldn't matter much, since the surface can be adjusted regardless of whether the tournament is indoors or outdoors (and this is specially true in pro tournaments),

For regular clubs and city courts, the surface matters the most. It's not getting changed or redone very often, so any adjustment is a long term factor in the speed and play of the court. Big tournaments of course do change the surface sometimes yearly, and the treatment presumably would be the same on every court, so the only differences should be weather related. And weather can make quite a difference, but not typically on the same scale as a surface treatment could potentially make, at least with hard courts.
 
Saying indoor conditions are slower than outdoors contradicts pretty much every experience we've heard from players.

An uncited reddit post is not going to change that.
Outdoors can play slower or faster than the same court indoors, depending on weather conditions. That reddit post has two links in it, one of which is Murray's opinion that W court played slower with the roof on. There's also the height of bounce issue which is not speed issue per se but is perceived as such. And without weather variables, flat shots work better indoors while spin is a little bit less useful.
 

d-quik

Hall of Fame
An uncited reddit post is not going to change that.
Why would humidity make the ball "slower"?
the so called uncited reddit post has two different sources one of which makes a compelling case and the other cites andy murray directly and also says other pros agree with him. Its like you didnt read the post at all.

Your humidity argument that involves the air density argument is sound, but their argument that the ball will absorb more moisture in humid conditions (making it heavier) also has merit. We are just trying to figure out which is more negligible.
 

tlm

G.O.A.T.
The reasons for any perceived change in speed are mostly due to the human factor. The short version is, with the wind variable removed, players can simply take bigger cuts at the ball. It's also generally cooler indoors, which makes usually results in faster play.

Changes in temperature and humidity also affect the players more than the flight or bounce of the ball. Hotter conditions generally make the ball bounce higher (slowing down play). Humidity doesn't affect the ball in flight a whole lot. Note that more humidity in the air makes it less dense, which should make the ball travel faster in flight.

But the biggest factor when temperature and humidity increase is the human factor. The hotter and more humid it gets, the quicker the human body will tire out, which is why hot and humid conditions "feel" slow. It's your body is slowing down - not the ball. So does closing the roof increase or decrease temperature and humidity? Well, that depends on how good the HVAC system is. But temperatures generally get cooler indoors and this makes it both more comfortable to play in, and it also makes the bounce lower.

Surface shouldn't matter much, since the surface can be adjusted regardless of whether the tournament is indoors or outdoors (and this is specially true in pro tournaments),


My experience is that on very high humidity like over 75% the ball slows down and I’m sure the ball absorbing moisture is part of the reason. In Illinois where I live the weather can go from 80% humidity one day then within a day or two go down to 30% and there is definitely a difference in the speed of the ball.

On very clear low humidity and high barometric pressure days the ball plays much faster, and no it’s not just from the difference in heat on the body. My hitting partners have noticed the same thing clear bright days with low humidity and the ball is tougher to control.

Back when I played softball it was the same affect on super humid evenings there would be very few home runs hit. But on less humid air with high pressure conditions the ball would carry farther and go faster.
 

jm1980

Talk Tennis Guru
the so called uncited reddit post has two different sources one of which makes a compelling case and the other cites andy murray directly and also says other pros agree with him. Its like you didnt read the post at all.

Your humidity argument that involves the air density argument is sound, but their argument that the ball will absorb more moisture in humid conditions (making it heavier) also has merit. We are just trying to figure out which is more negligible.

Outdoors can play slower or faster than the same court indoors, depending on weather conditions. That reddit post has two links in it, one of which is Murray's opinion that W court played slower with the roof on.
So what weather conditions make it faster or slower, and how are they affected by the presence of a roof?

With Wimbledon there is an additional and important variable: the surface itself. When the roof is closed, it's usually because it just rained. This makes the grass damp (affecting the bounce), and the moisture on the surface can make the balls wet, which makes them heavier and slower. So players may be wrongly blaming the Wimbledon roof for factors that don't have anything to do with the roof itself. With hard courts this is much less of a problem because they dry much quicker and they stay dry.

There's also the height of bounce issue which is not speed issue per se but is perceived as such.

The speed of the court is very much tied to the bounce. The ITF's CPR measurement of court speed is based entirely on how the ball bounces.


My experience is that on very high humidity like over 75% the ball slows down and I’m sure the ball absorbing moisture is part of the reason. In Illinois where I live the weather can go from 80% humidity one day then within a day or two go down to 30% and there is definitely a difference in the speed of the ball.

On very clear low humidity and high barometric pressure days the ball plays much faster, and no it’s not just from the difference in heat on the body. My hitting partners have noticed the same thing clear bright days with low humidity and the ball is tougher to control.
It's hard to separate the perception of slowness from your own perceived effort. Let's say you are used to hitting the ball with effort X and the result is it goes Y mph. Now you are tired. You still think and feel you are putting the same amount of effort but the result is not the same.

I think the ball absorbing moisture from the air could be a factor, but its effect would be greatly diminished in the pros where they constantly switch out balls, and they come in airtight cans. I suppose one way to test this would be to open a fresh can of balls and weigh them with a high end scale, and at the end of a particularly humid session you can weigh them again and see by how much the weight has changed

Back when I played softball it was the same affect on super humid evenings there would be very few home runs hit. But on less humid air with high pressure conditions the ball would carry farther and go faster.
That's an interesting observation because I looked up the effect of humidity on baseball and the consensus seems to be higher humidity results in more home runs, because the ball travels further in the thinner air:

It might seem like baseballs would have an easier time zipping through dry air. But in reality, hitters should have better luck batting balls in sweaty Miami than in arid Phoenix.

The reason has to do with the weight of gaseous molecules in the air. As air becomes more humid, it holds more water molecules. That gaseous water vapor is really light, and it displaces heavier gases like nitrogen and oxygen.

"By kicking out those heavy gases, the air density goes down," says Terry Bahill, a professor emeritus of engineering at the University of Arizona. Air density is a measure of molecules in a given amount of space; Bahill says it's a way of saying how heavy the air is. "If air has higher density, it's harder for the ball to go through it," he says. "There's more drag."


 

tlm

G.O.A.T.
So what weather conditions make it faster or slower, and how are they affected by the presence of a roof?

With Wimbledon there is an additional and important variable: the surface itself. When the roof is closed, it's usually because it just rained. This makes the grass damp (affecting the bounce), and the moisture on the surface can make the balls wet, which makes them heavier and slower. So players may be wrongly blaming the Wimbledon roof for factors that don't have anything to do with the roof itself. With hard courts this is much less of a problem because they dry much quicker and they stay dry.



The speed of the court is very much tied to the bounce. The ITF's CPR measurement of court speed is based entirely on how the ball bounces.



It's hard to separate the perception of slowness from your own perceived effort. Let's say you are used to hitting the ball with effort X and the result is it goes Y mph. Now you are tired. You still think and feel you are putting the same amount of effort but the result is not the same.

I think the ball absorbing moisture from the air could be a factor, but its effect would be greatly diminished in the pros where they constantly switch out balls, and they come in airtight cans. I suppose one way to test this would be to open a fresh can of balls and weigh them with a high end scale, and at the end of a particularly humid session you can weigh them again and see by how much the weight has changed


That's an interesting observation because I looked up the effect of humidity on baseball and the consensus seems to be higher humidity results in more home runs, because the ball travels further in the thinner air:

It might seem like baseballs would have an easier time zipping through dry air. But in reality, hitters should have better luck batting balls in sweaty Miami than in arid Phoenix.

The reason has to do with the weight of gaseous molecules in the air. As air becomes more humid, it holds more water molecules. That gaseous water vapor is really light, and it displaces heavier gases like nitrogen and oxygen.

"By kicking out those heavy gases, the air density goes down," says Terry Bahill, a professor emeritus of engineering at the University of Arizona. Air density is a measure of molecules in a given amount of space; Bahill says it's a way of saying how heavy the air is. "If air has higher density, it's harder for the ball to go through it," he says. "There's more drag."



On a hot humid day with the sun fully out the ball will still travel pretty fast, but on the same day only in the evening with the sun going down and courts are shaded the ball moves slower. Wether it be tennis or softball I found it to have similar affect. I notice the same thing when I’m fresh from the start so being tired has nothing to do with it.

There are times when the humidity will be over 80% in the evening where I play and even though it’s warm out if it’s shaded the ball slows down. I have hit at both midday and evening on the same day and there is a noticeable difference, all the guys I hit with notice the same thing.

Regardless of how many studies you show I can’t believe that the ball travels faster with high humidity conditions. I know on what we call bluebird days where the sky is clear and low humidity with high barometric pressure the ball flys around like a super ball. If a few days later and the conditions are warm with high humidity the ball goes much slower, I have hitting partners that like to hit aggressive shots and they will comment on how it’s not possible to hit winners in the heavy conditions.
 

toth

Hall of Fame
The reasons for any perceived change in speed are mostly due to the human factor. The short version is, with the wind variable removed, players can simply take bigger cuts at the ball. It's also generally cooler indoors, which makes usually results in faster play.

Changes in temperature and humidity also affect the players more than the flight or bounce of the ball. Hotter conditions generally make the ball bounce higher (slowing down play). Humidity doesn't affect the ball in flight a whole lot. Note that more humidity in the air makes it less dense, which should make the ball travel faster in flight.

But the biggest factor when temperature and humidity increase is the human factor. The hotter and more humid it gets, the quicker the human body will tire out, which is why hot and humid conditions "feel" slow. It's your body is slowing down - not the ball. So does closing the roof increase or decrease temperature and humidity? Well, that depends on how good the HVAC system is. But temperatures generally get cooler indoors and this makes it both more comfortable to play in, and it also makes the bounce lower.

Surface shouldn't matter much, since the surface can be adjusted regardless of whether the tournament is indoors or outdoors (and this is specially true in pro tournaments),
In humid condition tha ball will harder, it is more difficoult to make it fast.
 

jm1980

Talk Tennis Guru
On a hot humid day with the sun fully out the ball will still travel pretty fast, but on the same day only in the evening with the sun going down and courts are shaded the ball moves slower. Wether it be tennis or softball I found it to have similar affect. I notice the same thing when I’m fresh from the start so being tired has nothing to do with it.

There are times when the humidity will be over 80% in the evening where I play and even though it’s warm out if it’s shaded the ball slows down. I have hit at both midday and evening on the same day and there is a noticeable difference, all the guys I hit with notice the same thing.

Regardless of how many studies you show I can’t believe that the ball travels faster with high humidity conditions. I know on what we call bluebird days where the sky is clear and low humidity with high barometric pressure the ball flys around like a super ball. If a few days later and the conditions are warm with high humidity the ball goes much slower, I have hitting partners that like to hit aggressive shots and they will comment on how it’s not possible to hit winners in the heavy conditions.
In humid condition tha ball will harder, it is more difficoult to make it fast.
There is evidence that a ball that's been exposed to humidity will absorb the impact of the bat better, which makes its initial speed off the bat slower. The other variable with tennis balls is the fuzz - if the ball fluffs up then it increases drag, but it's inconclusive what the effect of humidity on that is. And again, pros change balls so regularly that it's hard to imagine these being much of a factor.

Humid air definitely has less drag than dry air though, so all else being equal, a ball should fly further and faster in humid conditions. There is no scientifically sound explanation for the alternative.
 

tlm

G.O.A.T.
There is evidence that a ball that's been exposed to humidity will absorb the impact of the bat better, which makes its initial speed off the bat slower. The other variable with tennis balls is the fuzz - if the ball fluffs up then it increases drag, but it's inconclusive what the effect of humidity on that is. And again, pros change balls so regularly that it's hard to imagine these being much of a factor.

Humid air definitely has less drag than dry air though, so all else being equal, a ball should fly further and faster in humid conditions. There is no scientifically sound explanation for the alternative.

Whatever you say jm. But you are the only person I know that thinks the ball goes faster in high humidity. Everyone that I play with says the same thing the ball slows down in high humidity. Like I already mentioned in midday with the sun out in high temperatures and high humidity the ball can still travel pretty fast but I think it’s more because of the heat not humidity. I’m not sure why you keep saying pro players change the balls frequently. How does that apply to amateur guys playing with 3 new balls for a couple of hours?

If you play in the evening in the shade and high humidity the ball slows down considerably. By the way do you even play tennis? Or do you just read studies? If you play please try comparing high humidity vs low humidity and then tell me the ball goes faster in high humidity.
 

jm1980

Talk Tennis Guru
Whatever you say jm. But you are the only person I know that thinks the ball goes faster in high humidity. Everyone that I play with says the same thing the ball slows down in high humidity. Like I already mentioned in midday with the sun out in high temperatures and high humidity the ball can still travel pretty fast but I think it’s more because of the heat not humidity. I’m not sure why you keep saying pro players change the balls frequently. How does that apply to amateur guys playing with 3 new balls for a couple of hours?

If you play in the evening in the shade and high humidity the ball slows down considerably. By the way do you even play tennis? Or do you just read studies? If you play please try comparing high humidity vs low humidity and then tell me the ball goes faster in high humidity.
What I think or feel is not important. Working in my field, I've learned to never trust my eyes and my brain, because they can be easily deceived. Our perception of reality often does not match up with actual reality.

If you tell me the ball slows down in high humidity, then you'll have to come up with a reason why because it contradicts the data and my understanding of the Physics involved.
 

tlm

G.O.A.T.
What I think or feel is not important. Working in my field, I've learned to never trust my eyes and my brain, because they can be easily deceived. Our perception of reality often does not match up with actual reality.

If you tell me the ball slows down in high humidity, then you'll have to come up with a reason why because it contradicts the data and my understanding of the Physics involved.

So does that mean that you don’t play tennis? One reason is the balls hold more moisture so they slow down, plus in all my years of playing tennis that I have played in heavy humidity the ball goes slower especially compared to a low humidity day. The difference is obvious and all the guys I play with say the same thing but I guess it’s just our perception.
 

jm1980

Talk Tennis Guru
So does that mean that you don’t play tennis?
Oh, I play. But I take an analytical approach to things

One reason is the balls hold more moisture so they slow down,
This does not any make sense because all else being equal, the heavier the object, the further it will travel in the air because it has smaller air resistance. If you throw a ball made out of feathers at 30 mph versus another, similarly sized but much heavier one made out of solid metal at 30 mph, which one do you think will travel further? Of course it's also more difficult to launch a heavier object - which means the initial speed is slower, but all else being equal (i.e.: same initial speed), a heavier object will travel faster through the air.

I suppose we are getting some definitions crossed here. Because strictly speaking, the effect of humidity on the flight of the ball itself is that it should speed it up. However, a ball that's been exposed to humidity absorbs the impact better, so a swing with the same effort does not result in the same initial launch speed. Obviously a ball that's been launched at 50 mph will travel further than one that was launched at 40 mph, but that's not because of the slower ball being slowed down in-flight. It already started out slower.

The difference is obvious and all the guys I play with say the same thing but I guess it’s just our perception.
I also don't know why you are taking this as some kind of personal attack. Everyone has these problems. The best we can do is to be aware of them and adjust our interpretations accordingly. It's like how everyone jumps on video footage here and underrate the players on them because of how much worse everything looks on video. It still looks bad to me; I just am aware that in real life those guys would look different and I adjust my assessment accordingly.
 
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tlm

G.O.A.T.
If the heavier ball goes faster then why are the regular duty balls lighter and they travel faster than the heavier extra duty balls? The lighter regular duty balls are used on clay courts because they aren’t as slow as the extra duty balls.
 

jm1980

Talk Tennis Guru
If the heavier ball goes faster then why are the regular duty balls lighter and they travel faster than the heavier extra duty balls? The lighter regular duty balls are used on clay courts because they aren’t as slow as the extra duty balls.
The extra duty balls have more fuzz in them, and using them on clay would make them pick up more clay, and make them heavy.

You are just not understanding the definitions. A heavier object (or rather, denser) travels faster through the air. If you could hit a heavier ball at the same initial speed off the racquet as a lighter ball, then the heavier ball would travel further. The problem is a heavy ball also requires more effort to hit if you want that same initial speed. So again, it's not that the heavy ball travels slower in the air; it's because it already came off the racquet slower.

At the end of the day, yeah, the heavy ball takes longer to go from baseline to baseline. But it's not because it travels slower - it's harder to hit it as fast.
 
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tlm

G.O.A.T.
The extra duty balls have more fuzz in them, and using them on clay would make them pick up more clay, and make them heavy.

You are just not understanding the definitions. A heavier object (or rather, denser) travels faster through the air. If you could hit a heavier ball at the same initial speed off the racquet as a lighter ball, then the heavier ball would travel further. The problem is a heavy ball also requires more effort to hit if you want that same initial speed. So again, it's not that the heavy ball travels slower in the air; it's because it already came off the racquet slower.

At the end of the day, yeah, the heavy ball takes longer to go from baseline to baseline. But it's not because it travels slower - it's harder to hit it as fast.

Right out of the can the extra duty balls are heavier than the regular duty and they are definitely slower. I play indoors on hard courts during the winter and some guys like the regular duty balls for indoors and it’s because they are faster. Please try regular duty balls indoors on hardcourts and then try the extra duty and then tell me about the heavier ball going faster.
 

jm1980

Talk Tennis Guru
Right out of the can the extra duty balls are heavier than the regular duty and they are definitely slower. I play indoors on hard courts during the winter and some guys like the regular duty balls for indoors and it’s because they are faster. Please try regular duty balls indoors on hardcourts and then try the extra duty and then tell me about the heavier ball going faster.
Again, if you say heavy balls travel slower in the air, the science does not agree with you here.

An extra duty ball would result in slower player for a few reasons:

1. You aren't able to hit it as hard because it's heavier
2. The extra felt absorbs impact better, making it slow down more when it hits the racquet and when it hits the ground
3. The extra felt increases the drag in flight - but that's technically because of increased surface area, and not increased weight.

1 & 2 are unrelated to how it travels in the air once it's already been hit.
As for 3, it's like a pound of feathers dropping slower than a pound of bricks. They both have the same weight, but the feathers' larger surface area increases its aerodynamic drag
 
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d-quik

Hall of Fame
Jm1980 and tlm have to stop WOOSHing each other.

Both arguments dont cancel each other out, but go past each other

One is arguing how hard it is to accelerate a heavier ball VS how hard a heavier ball flies once IT HAS ALREADY ACCELRATED.
 
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