Coco Gauf’s Second Serve: A Technical Analysis

[johnyandell]

Let's get your thoughts on Sean O'Neil's article, "Coco Gauf’s Second Serve: A Technical Analysis"

[jimlosaltos]

Just some stats on this topic that might be of interest to readers.

For the tournament, Coco Gauff played 5 matches and had 23 double faults vs 75 points won on second serve.
Her average second serve speed in the semifinal was 90 MPH and she won 10 of 31 points behind her second serve that day.

https://www.rolandgarros.com/en-us/matches/2024/SD002

[stroke]

Just some stats on this topic that might be of interest to readers.

For the tournament, Coco Gauff played 5 matches and had 23 double faults vs 75 points won on second serve.
Her average second serve speed in the semifinal was 90 MPH and she won 10 of 31 points behind her second serve that day.

https://www.rolandgarros.com/en-us/matches/2024/SD002

That seems like too many doubles.

[clewit]

Thanks for the article Sean.

1. In the Back Bend part, Coco is hitting a kick serve from the ad court but are Raonic and Sinner also hitting kick serves? Sinner is hitting from the deuce from a different camera angle. This makes it hard to compare. Also, cervical and thoracic extension are important for the kick serve and many top pro servers have significant cervical and thoracic extension in their spines. This does not mean they will get injured. Some pros, perhaps Sinner and Raonic, may hit with less arch in their backs. It's also hard to determine the angle of the arch in the spine from high speed video due to clothing that the athletes wear.

2. In the Upward Swing and Followthrough section, it looks like Coco is hitting a kick serve but Raonic and Sinner are hitting flat power serves. This makes comparing internal shoulder rotation potentially flawed between the Coco and the others. The long axis pronation will look different for a kick versus a flat power serve.

3. Coco does drop her head and should probabably keep it up longer into the impact. That's a good habit. But there are also many pros who do not keep their heads up at impact and still serve very well. That head dropping just before contact may not affect her serve delivery as much as we think.

Thanks for commenting.

Chris

[clewit]

Also, We should be cautious to draw a direct link between pulling the head down and risk of injury in the shoulder and abdomen. I am not aware of any research study that shows a correlation or causation between the two. There may be a link, but there may not be. We do not know for sure why Venus suffered from abdominal injuries--we can only surmise. I believe Dr. Brian Gordon has demonstrated excessive activation of the abdominals from an early entry into the racquet drop, in his private research, what Dr. Kibler would describe as the "pull" serve. Even then, I don't think Dr. Kibler or Dr. Brian Gordon can point to any definitive peer reviewed study linking the "pull" type serve to higher injury rates in the shoulder and abdominals. We should be cautious making statements about injury risk that are not evidence-based. That's my main concern.

Thanks
Chris

[seano]

Chris -

Thanks for your comments. One of the reasons I appreciate Tennisplayers.net so much is the wealth of knowledge it has from Industry leading researchers like Dr. Brian Gordon and Dr. Ben Kibler. There are multiple articles from both Dr. Gordon and Dr. Kibler on the website. I appreciate your view of being cautious about drawing direct links between injuries and possible causations, very valid opinion. My point was to be careful of putting unnecessary stress on joints or body parts because of ones technique. Dr. Kibler discusses the point of putting undue stress on the shoulder and lower back with the "pull down" serve method, in his "push up" vs. "pull down" video.

An answer to being able to put scientific data into stroke analysis and development may be right around the corner. Over the last several years I've been fortunate enough to be able to spend time each year with Dr. Brian Gordon in Boca Raton and discuss technique. He's been very generous with his time. I believe it's in next month's issue, that another article I wrote will be about Dr. Gordon's affiliation with the German company "Simi" in developing a "markerless motion capture" system. This 3D Motion capture produces a 3D "mapping" of a stroke. 3D quantification is the most sophisticated form of information that can be used for stroke development. It's a very rare, very expensive system with maybe a handful of them in the world. It may be able to finally answer all these complicated stroke analysis questions. In the past, Brian has had to use the cumbersome and time consuming method of placing up to 70 sensors on a student/racquet to be able to get this data. Now it will be "markerless" and you'll be able to receive the data in real time. Very interesting times ahead for tennis stroke research.

Sean

[stotty]

Congratulations on a super article, Sean.

A couple of questions: With regard to Coco's racket drop, when you say the racket goes past her left shoulder, does this mean her racket head doesn't pass through the centre of Coco's head...as BG puts it? It's hard to tell from the clip. If so, how does one correct that?

I have a girl on probation. I have synched the leg drive but the racket head doesn't quite pass through the centre of her head. Would this be because her elbow in probation is set slightly too low? Would having a lower than 90 degree elbow in probation (or more correctly an elbow that sinks slight before descending into the backswing) be the cause of the problem? It's not major like Coco's but all the same it would be nice to strive for perfection.

[seano]

Stotty -

Thank you for the compliment. To answer your questions:

1) Coco's racquet drop - You are correct in your interpretation. If you are looking at Coco from a front side view, ideally the racquet head would disappear behind her head. In Coco's case, her racquet head will go way past her head and even slightly past her left shoulder. She does this only on her 2nd serve, her 1st serve is much closer to behind her head. The interesting thing is that her racquet drop wasn't this pronounced in August 2023 when I also took footage at a tournament. Something changed.

2a) The racquet drop correction could be done 2 quick ways that come to mind. 1) Stand so you are facing your students back side (side view). Touch the tip of your racquet head against her left (for a righty) shoulder blade (your racquet is perpendicular to the line of their back). As the student drops their racquet behind their head, their racquet should not touch your racquet. If it does, they have gone too far forward. The racquet should drop more over the right shoulder blade than their left shoulder blade. I learned that from Dennis Van Der Meer, when I was the director at one of his tennis centers.

2b) The second method, I'm not as familiar with but BG showed it to me this March when I showed him my footage of Coco. He stood behind me with a PCV tube about shoulder height, parallel to the baseline and my racquet dragged along the pipe till it naturally fell behind my head, like it's supposed to. I need a better visual of this method being done to fully understand it.

3) Elbow position in trophy - I would need to see video of her elbow position but in general I have seen plenty of lower than 90 degree elbow positions that were able to have the racquet head disappear behind the head. For a lower elbow in trophy, I've had success with either tying a towel around a students upper arm (cover bicep and tricep) and they can feel when the towel touches their side. Instead of a towel, I have also used one of those little kids floaty arm devices that kids wear so they don't go under water. Place the blown up device around your students upper arm, like you did the towel. The blown up device will hit their side when the elbow has dropped too low.

Hope that's clear and makes sense.

Sean

[stotty]

Stotty -

Thank you for the compliment. To answer your questions:

1) Coco's racquet drop - You are correct in your interpretation. If you are looking at Coco from a front side view, ideally the racquet head would disappear behind her head. In Coco's case, her racquet head will go way past her head and even slightly past her left shoulder. She does this only on her 2nd serve, her 1st serve is much closer to behind her head. The interesting thing is that her racquet drop wasn't this pronounced in August 2023 when I also took footage at a tournament. Something changed.

2a) The racquet drop correction could be done 2 quick ways that come to mind. 1) Stand so you are facing your students back side (side view). Touch the tip of your racquet head against her left (for a righty) shoulder blade (your racquet is perpendicular to the line of their back). As the student drops their racquet behind their head, their racquet should not touch your racquet. If it does, they have gone too far forward. The racquet should drop more over the right shoulder blade than their left shoulder blade. I learned that from Dennis Van Der Meer, when I was the director at one of his tennis centers.

2b) The second method, I'm not as familiar with but BG showed it to me this March when I showed him my footage of Coco. He stood behind me with a PCV tube about shoulder height, parallel to the baseline and my racquet dragged along the pipe till it naturally fell behind my head, like it's supposed to. I need a better visual of this method being done to fully understand it.

3) Elbow position in trophy - I would need to see video of her elbow position but in general I have seen plenty of lower than 90 degree elbow positions that were able to have the racquet head disappear behind the head. For a lower elbow in trophy, I've had success with either tying a towel around a students upper arm (cover bicep and tricep) and they can feel when the towel touches their side. Instead of a towel, I have also used one of those little kids floaty arm devices that kids wear so they don't go under water. Place the blown up device around your students upper arm, like you did the towel. The blown up device will hit their side when the elbow has dropped too low.

Hope that's clear and makes sense.

Sean

Thanks so much for your considered reply and your help. I will try 2a and see what develops from it.

The reason I asked about the elbow position is that BG suggests an angle of 90 degree (slightly lower is acceptable) and that the racket be positioned far away from the head. BG states he doesn't want the elbow any lower but doesn't state why exactly. When I get my student's elbow at 90 degrees it does reduce forward entry but not entirely, so I wondered if the elbow position plays a significant part in getting the racket to pass the centre of a player's head.

Probation is a hell of a patient job but in the space of a month I have made significant progress with my student. I have taken the decision to start most students off this way as it gets things off to a better start, and especially in the case of girls.

[seano]

Totally agree about starting students in probation.

[seano]

If you refer to Dr. Gordon's video "The Hesitation Point" found under the Biomechanics section, around the 4:00 mark till the end, he gives a great explanation/demonstration of what the forward entry looks like and the problems involved with it.

[jimlosaltos]

Cross posting from "Coco's New Coach ... " to push this thread up, and surface the article with a technical analysis of issues with her serve.

Here's Sean O'Neal's article at this link, which breaks down her second serve technique.

The impact of these problems: Jeff Sackman of Tennis Abstract dissects the numbers to show the enormous impact Coco's double fault problems have on her performance. Starting with the best return stats on the WTA, and a first serve on par with or better than Sabalenka and Rybaknia, cut the doubles in half and she leaps past them. Eliminate them and she's the best.

~~~~~~
Jeff says that if Coco fixed her second serve she would, statistically at the least, become the best WTA player in the world. Here's an excerpt:
.
.
By service points won--where the double faults come into play--Gauff ranks a more pedestrian 12th. That's entirely because of the deliveries that miss. She wins more first-serve points than anyone except for Qinwen Zheng and Elena Rybakina. In an era without megastars, the combination of 1st or 2nd on return and 12th on serve might be good enough to lead the field, but with an all-rounder like Swiatek and a dominant slugger like Sabalenka to contend with, it doesn't do the job.
.
Here, then, is the what-if. Wave a magic wand and proclaim that all of Gauff's second serves find the box. The 9% of her service points that end in double faults turn into second serves in play: points that she wins at a 56% clip.
.
Do that, and her rate of serve points won--currently at 60.2%, good for 12th place--becomes 65.3%, better than anybody. A double-fault-free Coco Gauff would rack up more serve points than anyone on tour, while still winning almost as many return points as Iga does. A handful of key points might swing the year-end number one in either direction, but statistically, the American would be the best player in the world. {He goes further "Take away half of her double faults, and at the very least she looks stronger than Sabalenka and Rybakina.}

[don_budge]

Let's get your thoughts on Sean O'Neil's article, "Coco Gauf’s Second Serve: A Technical Analysis"

If you refer to Dr. Gordon's video "The Hesitation Point" found under the Biomechanics section, around the 4:00 mark till the end, he gives a great explanation/demonstration of what the forward entry looks like and the problems involved with it.

I read your analysis of the Coco Gauff second serve and a number of things came to mind. I'm a little out of practice in writing about tennis so please beg my pardon. The problem with Coco's second serve is that she missed her first serve. This is a very important point. Does she have a problem with the second serve that is different from her problem with her first serve? I really doubt it. Moving on...in the article you go to great lengths about this and that regarding her lack of synchronicity. I believe that this is basically where the problem lies. The funny thing is that you have compared two men's serves to Gauff's serve. The two men serve from the platform position while Gauff is a pin point server. Sinner is a pin point server currently but it appears that the examples that you use are him using platform.

So by using two platform servers as "good" examples to her "bad" form you have more or less solved the puzzle. It seems to me that a lot of the pin point servers look to be rather "homemade" in their motions. The bits and pieces don't flow without any kinks in the motion and this is where her problem lies at the root cause. When I look at the motion from the setup to backswing...I see some stuff that needs to be ironed out. Starting them out at hesitation point is one thing, but the other is you have to get there first. All your ducks have to be in a row once you arrive at this critical junction of the serve.

Gauff has an unusually live arm for a woman. She is very athletic and she makes this serve work much of the time. She reminds me of the Russian that she lost to in this regard. But both players would be better served by using platform. A critical element of serving is tempo. Maintaining that tempo in situations where things get a bit nervy are enough to derail any serve that is not friction free. Gauff introduces a lot of friction with her self made backswing. From there on out it is a series of subtle compensatory moves that provide a rather fragile basis for her motion. You pointed out serveral of these moves that don't line up with the men's examples. She is a good enough athlete to make it work but there are going to be times and situations where things get a bit dicey and if she is not firing on all eight...she is going to feel and be aware that not everything is smooth sailing.

I didn't see the match against the Russian but I did watch the last couple of games. The double fault on match point is a real no no. Was the problem with the second serve? I believe that a great server is going to be entirely focused on getting that first one in...particularly so if they know that the second is unreliable. Especially on match point. She has a problem with her motion. The extra movement with the feet moving around do not provide the stable base needed for the motion to be a thousand percent reliable. The thing is that modern serve motions are designed for speed when the entire equation is one of speed, spin and placement. If you want to be able to combine these three elements of control to maximize "power" it is best done from the platform stance. From this stance you can begin to address the path of the backswing to arrive at the hesitation point with perfect balance and proper timing which will easily remedy her issues with tempo. Once the player gets a bit nervy the tendency is to rush the motion and once you do that you are going to be more erratic.

Ooops...I substituted "hesitation for probation". But...I actually like that. It is a bit of a hesitation or a pause at the top. An indication of perfect balance and poise. Tell Dr. Gordon I said so.

[seano]

DB -

Enjoy your analysis and insight, your commentary adds a different dimension to the forum. I agree with you on several of your points. I'm totally a "platform stance" guy and agree about not flowing without kinks in the motion. Coco absolutely has a unusually "live" arm. The part that the videos didn't show well enough was that there is a difference mechanically between her 1st and 2nd serve. The racquet head drops more or less behind her head on her 1st serve. On her 2nd serve however, the tip of her racquet head often times goes approximately a racquet head length beyond her left shoulder with the face pointing almost flat towards the ground. I've tried to upload a very short video of it, with no success. I've taken high-speed slow motion video of Coco's serve from August 2023 (DC) and March 2024 (Miami) of her serve and the 2024 video version is worse than 2023. I purchased a new camera (Panasonic G9II) and the recording speeds are to much for my older video analysis software to edit. I'll need to find a more updated software that can handle these new recording speeds. I'm presently spending a month in beautiful Dingle, Ireland and don't have access to my videos.

[jimlosaltos]

DB -

Enjoy your analysis and insight, your commentary adds a different dimension to the forum. I agree with you on several of your points. I'm totally a "platform stance" guy and agree about not flowing without kinks in the motion. Coco absolutely has a unusually "live" arm. The part that the videos didn't show well enough was that there is a difference mechanically between her 1st and 2nd serve. The racquet head drops more or less behind her head on her 1st serve. On her 2nd serve however, the tip of her racquet head often times goes approximately a racquet head length beyond her left shoulder with the face pointing almost flat towards the ground. I've tried to upload a very short video of it, with no success. I've taken high-speed slow motion video of Coco's serve from August 2023 (DC) and March 2024 (Miami) of her serve and the 2024 video version is worse than 2023. I purchased a new camera (Panasonic G9II) and the recording speeds are to much for my older video analysis software to edit. I'll need to find a more updated software that can handle these new recording speeds. I'm presently spending a month in beautiful Dingle, Ireland and don't have access to my videos.

Great input, seano.

Re: Video. If you're shooting H.265, for the high frame frames, on a Mac the codec to process the video ships with your OS. So, might need to update that. We stumbled across that the hard way for TPN. I haven't used Windows in a few years, so can't comment.

Enjoy Dingle !