# A controversial question about line calls

Discussion in 'Adult League & Tournament Talk' started by sureshs, Sep 23, 2013.

1. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
We all know that if the ball is 1% in, it is in.

What if you think that there is more of a chance that it was out than it was in, and it is not 51-49, but say 95-5? Obviously, you did not see the ball good enough to be 100% sure one way or the other.

If a surgeon thinks 95 to 5 that a tumor should be removed at once, should he not do it?

2. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
It is not a matter of probability.

Fact is that the ball is either in or out.

If I see it out I call it out, if not I continue to play.

3. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
The fact is what it is. If it was so easy, there would be no Hawk-Eye.

4. ### tennixplRookie

Joined:
Apr 22, 2013
Messages:
281
Location:
SA Texas
yeah but if your opponent disagrees wouldn't you just call a let and play it over? and it is about probability since there are close calls and your brain adjusts and makes an image up in your head on where you "think" it landed. how do you call a long serve long since unless it is really long you cant see line-green-ball? bc you use assumption and probability based on where you see it bounce to determine whether it is in or out.

Sureshs:
"We all know that if the ball is 1% in, it is in." -- you are funny, there are plenty of people who don't "KNOW" this. watch some GOAT 3.0-4.0s at a tournament and this is easy to disprove.

Call em as you see em and be fair! If you don't clearly "see" it out it is in.

5. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
You are not getting it, it is a fact that a ball is in or out, it is not probabilistic, the issue is our ability to measure this fact.

If I see it it out it is out in all other cases it is in.

I am not sure what your problem in understanding is, I mean a tennis ball is not some quantum object which location is indeed probabilistic, a tennis ball however has a definite location, and again it is in fact either in or out.

You can spin it, twist it, what if it, but what it, the answer still remains the same.

6. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
That is what I am getting at. What is "clearly"? If I think it is 95% out, what should I call?

7. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
If I see a ball clearly out I see it clearly out and that is not subject to discussion. However under certain circumstances I may agree with a let for the sake of peace. But obviously agreeing to a let does not imply I admit I was wrong.

Nope, you are wrong, whether a ball is in or out is a fact, it is not a probability. This indicates to me that perhaps you call balls out in cases where you actually did not see it go out?

8. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
What you think is obviously your business, all I can say to you that it does not make any sense, a ball cannot be 95% out, it is absurd. A ball is either 100% in or 100% out.

9. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
Isn't that obvious? When a person makes a call, isn't it about his ability to measure?

Why is it that HawkEye is used? Instead, shouldn't everyone just repeat what you are saying?

BTW, HawkEye also has an error margin of a mm or two.

10. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
Accurate but useless statement.

11. ### TimeSpiralProfessional

Joined:
Jul 9, 2013
Messages:
1,291
Location:
Gotham City
A ball that is 99% out is 100% in, that's my philosophy.

I get what you're saying, I just believe the sportsmanlike thing to do is give the benefit of the doubt to your opponent. There are several factors at play here.
1. Calling lines is hard to do. Pros have dudes staring at the lines for the express purpose of calling the lines, and they still mess up.
2. Playing tennis is hard to do. Combine playing tennis with calling lines, and you have something that is doubly hard to do.
3. Your eyes play tricks on you. They do. Even if you think they don't. We see in a "frame rate," and when the ball is in flight, you're actually seeing an approximation of several locations at the same time (trails, for lack of a better term). This can actually make detecting the exact location of impact difficult.
4. The ball is in contact with the ground for a period of time, longer than you might expect (1).
5. Even when watching tennis on an HDTV, calling the lines is almost impossible, because the framerate is not good enough.
6. Sometimes you'll hear guys say "I saw a sliver of [COLOR]. The ball was out," and they'll pinch off a quarter inch of air. I think to myself, "Bro. That's a little close to call out, you know?" But I always let their call stand. Sometimes I will ask, "How far out?" I hate seeing the pinch of air ... BS, I say. Because the ball is in contact with the court for a period of time, an "good" ball can "appear" to be out by a sliver or more.
It is for some of these reasons, and probably more, than you must call the ball "good" unless you are 100% it was out. There have been times where I thought the ball was out for sure, but I didn't actually see it, so I had to call it as good.

Sometimes, in fact, I will give too much and call a ball good that was 100% out because I didn't want to correct my initial call that it was good. I should probably work on that ...

Last edited: Sep 23, 2013
12. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
Obviously, we are talking about cases where the player cannot see the ball too clearly but yet can see it, and strongly feels it is out, but cannot vouch for it in a court of law.

13. ### tennixplRookie

Joined:
Apr 22, 2013
Messages:
281
Location:
SA Texas
you think it is 95% out then it is in. if you think based on what you saw and can comprehend there is a 95 out a hundred chance it is out. Well sorry call it in.

The real question to me is if you "saw" it out, but since most of us on TT are human, there is a 5% chance it was in;what do you do?

My answer is i saw it out so it is out, if i think i am wrong then i correct myself and call it in. if i saw it out and think it might have been good i call it out as i am not a line judge nor am i paying for one, i made my honest call. And no i don't care about histrionics on the other side of the net my call stands!

14. ### tennixplRookie

Joined:
Apr 22, 2013
Messages:
281
Location:
SA Texas
yeah but do you see him as accurate but useless or do you just think it?

15. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
Yes.

So then what is wrong about using this simple flowchart.

1. Opponent plays a ball.
2. Did you see it went out?

Answer: Yes -> the ball is out.
Answer: No -> the ball is in.
Answer: No, but I am 95% sure it was out -> the ball is in.
Answer: No, but my gut feeling tells me it was out -> the ball is in.
Answer: No, but based on the angle and spin it was out -> the ball is in.
Answer: No, but I did some probabilistic reasoning that showed it out -> the ball is in.
Answer: No, but it was really foggy -> the ball is in.
... and 600 more excuses

16. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
So far, I have done exactly that.

But a few weeks ago, I was watching an Open tournament at my club, and in the women's semifinal between two college players, the umpire had to be called. The ball was being hit hard close to the lines, and even we as spectators could not be sure. In one instance, I thought the ball was just in (caught the outer edge of the line), but the opponent called it wide. She was neither too close nor too far from the ball. I wondered what I would have done if I was in that position, because, if a large number of shots are close to the lines, it doesn't seem fair to say that the receiver should call all of them good because she could not say it was 100% out.

17. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
OK good for you.

You probably also don't understand why certain cases go to a jury. If no one actually saw the guy commit the crime, we should let him go in spite of the fact that he knew the victim, had threatened him before, was seen in the neighborhood 30 minutes before, and was fleeing the state boundary. But no one actually saw him kill.

18. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
I think it is totally fair.

And I think it would be cheating if someone decided to purposely call a ball wide because his opponent made already too many shots near the lines.

19. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
Um, what.......

Look, do what you want to do, it is after all your call! So if want to purposely call a ball you did not see out as out because someone already had too many balls near the line you could not call out then I suppose you should feel proud about that, but I would call it plain and simple cheating.

20. ### TimeSpiralProfessional

Joined:
Jul 9, 2013
Messages:
1,291
Location:
Gotham City
Sure it can! Come on, now. Don't be silly.

(Above) the proper sized tennis ball shows the last location where the ball is making contact with the court. The far end of the smear is the possible first location it contacted the court.

Tennix is right, you know. Your brain is approximating the location where the ball hit, you react based on that data, then you are conscious of what happened. Your brain, can definitely--and this is not debatable--be 100% certain and 100% wrong.

21. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
I don't think it is fair in high-level play where the stakes are high and a large percentage of balls are being hit close to the lines.

I think the fairness lies in assessing the probability honestly, like a jury is supposed to do.

If you think the probability is 90% it was out, it should be called out. Of course you should take into account what is your positioning was, but again not call it out because you were not looking at it from 6 inches away.

22. ### J_R_BHall of Fame

Joined:
Jan 27, 2010
Messages:
2,693
Location:
Newtown, PA
"See a ball out" with what amount of certainty is the question. Of course everyone knows that it's either in or out in fact, but we can perceive that fact with a varying amount of certainty. If I'm looking straight down a line and a ball bounces 3 inches outside the line while I'm looking straight at it, my certainty over the call is going to be pretty much 100%. If the ball is, in fact, the same 3 inches out but I'm standing in the service box by one sideline and the ball is just off the other sideline near the baseline, my certainty over whether it was in or out may only be 75% or something. It was, in fact, out by the same 3 in, and I think I saw it out, but because of the angle of my perception and the speed of the play (and the inherent fallability of my eyesight/perception), I can't say with 100% certainty. Do you make that call? If you only call lines that you are 100% certain about, either shots that you are looking directly at or that are so far out that the call is self-evident, you are going to give away A LOT of calls and A LOT of points, most of which would not be questioned by your opponent because they are in fact out.

The question is about probabilistic type 1 vs type 2 errors. A type 1 error is rejecting the null hypothesis when it is in fact true. A type 2 error is rejecting the alternative hypothesis when it is in fact true. In this case, what is distributed stochastically is your perception of the location of a ball's bounce vs the actual location (in vs out). A type 1 error is calling a ball out that is in fact in. A type 2 error is playing a ball that is in fact out. If your perception is not correct 100% of the time for a particular shot, then there is a give and take between type 1 and type 2 errors. In the first example of the shot while looking at the line, your perception is nearly 100% accurate, so you can say you will only call the ball out if you are 100% sure it was out. The odds of a type 2 error on that shot are minimal (say <1%), so it's acceptable. In the case of a shot that lands where you perceive it out but you're only 75% certain it was out (i.e. your perception is only correct 75% of the time and there is a 25% chance of a type 1 error)? Do you call it out anyway? If you don't, there is a 75% chance you're making a type 2 error. The question is, what is the threshhold probability for a type 1 error that you are willing to accept knowing that the probability of a type 2 error is 1-alpha?

23. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
Nope, what we think may or may not be conform reality. Reality is the ball is in or out, zero probability, fact are facts. Our minds may determine a ball to be in or out but that is all it is, all in the mind, and clearly it is secondary to the facts.

24. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
No, you missed the point again. It is not about compensating for the number of balls, but on making a probability call on each one. If a large number of balls are close to the line, and the next one looked like 50% out, it should be called in. The issue is when it looks like 90% out.

The number of balls was just an example to show in which cases this issue really matters.

25. ### tennis tomHall of Fame

Joined:
Jun 15, 2007
Messages:
2,838
This one is too easy, The Code says benefit of the doubt goes to the opponent--"think" equals doubt. If your're not 100% sure, it's opponent's point. I don't see anything "controversial" about this.

Last edited: Sep 23, 2013
26. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
You still don't get it that there is no neutral instrument here which can say for certain if it was in or out, and that the responsibility of the call has been left to the player for precisely this reason? Otherwise the Code could simply say: no match shall be played without linespersons, umpire, and Hawk Eye.

27. ### J_R_BHall of Fame

Joined:
Jan 27, 2010
Messages:
2,693
Location:
Newtown, PA
This is the knee jerk reaction among purists, but the reality is that, if people actually abided by this 100% absolute certainty requirement, they would play dozens of out balls every match, and they don't. Whether you admit it or not, there is not threshhold of uncertainty that everyone will accept (subconsciously in most cases).

28. ### TimeSpiralProfessional

Joined:
Jul 9, 2013
Messages:
1,291
Location:
Gotham City
lolwat?

We're talking about humans playing tennis right?

And damn ... my graphic got buried already : / I worked hard on that.

29. ### J_R_BHall of Fame

Joined:
Jan 27, 2010
Messages:
2,693
Location:
Newtown, PA
AWESOME GRAPHIC, DUDE!!!!! LOL.

30. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
You either saw that a ball was out or you did not. If you were not quite sure, or you thought it might be out, or you figured it out because you blinked, or whatever. All these things mean one simple thing: you did not see it out!

For me it is very simple:

Did I see it out?
Yes -> I call the ball out.
No -> I continue the play.

31. ### TimeSpiralProfessional

Joined:
Jul 9, 2013
Messages:
1,291
Location:
Gotham City
We might be getting trolled here, Suresh.

YES!

And you know ... on some surfaces the ball might even be in contact for longer than that : / At the rec level we're probably, in all likelihood, getting MURDERED on out calls that were good. This is another reason why I default to "good" even if I think I see a sliver.

Last edited: Sep 23, 2013
32. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
Have you ever seen this being acknowledged in the days before Hawk Eye and replays? Did pros just give up or did they argue with the linesmen and umpire based on what they thought? We are talking about high-level play here. For the two college girls, it was an important match. Each had her own contingent, one of them even had a father who illegally coached her during changeovers (I was sitting near him.)

33. ### brokenRPMRookie

Joined:
Apr 23, 2013
Messages:
199
Location:
tw@gmail.com

it's the lineman's job to call the lines correctly. I don't think many of us are trained to play and make the right calls all the time. that takes away the fun.

surgeons makes calls about tumors based on how much money they can make. so do dentists.

34. ### J_R_BHall of Fame

Joined:
Jan 27, 2010
Messages:
2,693
Location:
Newtown, PA
If you hold yourself to this 100% absolute certainty standard, then you clearly play dozens of out balls every match for which we don't have 100% certainty. Most people do not, and I think you're probably lying to yourself if you think you do.

35. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
Right. And that should mean that we should call all balls in, right? I mean, how can an untrained club player make any call at all when even players, umpires and linespersons taken together have been shown wrong by Hawk Eye? Surely a club player cannot trust his judgement and every ball must be called in.

36. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
And the problem with that is?

Why would I lie about that, to me tennis is a game, winning is great, loosing is so so, but the enjoyment comes from the playing and knowing to be fair to the opponent and to me that means to only call a ball out when I see it out.

Last edited: Sep 23, 2013
37. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
Why hasn't Cindy chimed in yet?

38. ### tennixplRookie

Joined:
Apr 22, 2013
Messages:
281
Location:
SA Texas
well since the rest of aren't a god like you we must use the measly instruments of eyes and brain to determine if the ball is in or out. we cannot ordain fact out of mere will like you.

some of us are even cursed to wear glasses which alter with slight degrees the light hitting are already imperfect eyeballs which even adds to the error of our ability to comprehend the "fact" of the ball being in or out.

then how do we even know if our mere observance of this "fact" did not in fact alter the universe and cause out to be in or in to be out. Oh my the horror for those of us who have to use our brains. see schrodinger cats if you don't get it.

39. ### tennixplRookie

Joined:
Apr 22, 2013
Messages:
281
Location:
SA Texas
Cindy will say that if you don't see it out then the ball is in.

95% out or not, by mere admitting that you only saw 95% out then it would be called good.

100% out or it is called good! any error in that approach if reciprocated will even out in the end all other things being equal.

ever seen a study of after the fact calls on just how many line calls the officials miss. of course that would dependent on "shot spot" which still has a millimeter error I believe IIRC.

If you really want to worry that much there are some really nice 1,000,000,000 frame per second cameras out there you can buy and place on the lines. Though they do run several million dollars last I checked.

40. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
It is simple, really. If you wear glasses, you are introducing one more layer of artificial materials between the ball and your eye and cannot be trusted - most likely you will be rejected for a pilot's job. You must call all balls in.

41. ### tennixplRookie

Joined:
Apr 22, 2013
Messages:
281
Location:
SA Texas
Actually there is a waiver for that like all things in the AF, don't know about private sector.

and i don't always play with them bc there are times when I'll take the slight out of focus approach to the slight not being sure of where the ball is approach, though it does make seeing the lines crisply tougher, but again it just means more balls in for opponent.

42. ### SilentSemi-Pro

Joined:
May 6, 2007
Messages:
799
If I'm not 100% certain the ball is out, then I "call" it in.

That doesn't mean I'm right on every call, but I believe it's the most respectful and honest way of dealing with the problem.

Win or lose, I feel good about myself playing this way, and that's the most important thing.

43. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
I applaud you for your attitude and sportsmanship!

44. ### LackRookie

Joined:
Aug 26, 2013
Messages:
214
You always call the ball in if you "think" the ball is out. Simple as that.

45. ### tennixplRookie

Joined:
Apr 22, 2013
Messages:
281
Location:
SA Texas
so if i am at net guy lobs me and I hear it hit fence before bouncing i call it in?

do you really watch the ball to bounce every single time even if a person shanks it off the court? or even obviously wide or long?

sorry but in those cases you are only "thinking" the ball is out.

46. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
I also do that because I am a rec player. In fact, I have experienced the anger of doubles partners because of my in line calls which contradicted their out calls. I am known as a pushover and some doubles partners don't like my honesty.

But if I was a pro or a college player, I would certainly think twice about this matter.

47. ### SilentSemi-Pro

Joined:
May 6, 2007
Messages:
799
And you hit the nail on the head.

At the rec level, let's just enjoy ourselves. That doesn't mean I don't want to improve, take up lessons, go to the gym to improve my fitness, win and all of that good stuff. However, because it's not my job, I can afford letting points go once in a while if I'm not 100% sure the ball was out. I might even win the point anyway !

If I were a pro or on the road to being one, I'd certainly see it differently, because my career would depend on it. I'd like the calls to be right, all the time. That's why I disagree with hawkeye being on only a couple courts. It should be on all courts, or on none at all. I know it's a money thing, but between you and me, the money is there: just spend it already.

Tennis, like golf, remains a sport of honour. There is no getting around that fact and in the end, I think I have to do what makes me feel right.

I cetainly trust my opponent feels the same way. I'm probably wrong some of the time, but when I leave the court, I can do it with my head held high.

48. ### newpballLegend

Joined:
May 28, 2013
Messages:
5,695
Location:
Northern California, USA
Wow, sound like a complete 180 turn to me.

49. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
But fundamentally, I don't see anything wrong in using probabilities in a probabilistic situation. Finance, economics, strategic planning, disaster preparation all use probabilities. No one says that if the probability of a hurricane damage is small, we should declare that the hurricane will never hit. Whether you are honest about the probabilities is the real question.

50. ### sureshsBionic Poster

Joined:
Oct 1, 2005
Messages:
36,207
No, it is an exploration of situations. not about what I do or don't do. The topic fascinates me.

I am the footfault guy, if you remember. I like to go around the club calling footfaults in rec matches before I get chased out.