Dr. Jack Groppel: Laws, Principles and Preferences In Tennis

Hey, everyone. On today's episode, we've got Dr. Jack Grappel. He's a globally recognized pioneer in sports science, human performance, and leadership coaching who's earned his place in the United States Professional Tennis Association Hall of Fame.

On today's episode, we discuss the differences between a law, a principle, and a preference, what's so easy about the game of tennis, and what he's currently working on with his three five doubles players. So sit back, relax, and prepare to become a smarter tennis player.

All right, Dr. Grappel, welcome to the pod. Hey, John, great to be with you, man. I feel like I'm in the presence of a legend, even though we are on opposite sides of the country right now. When I emailed you to set up this podcast, I asked you something that you're passionate about.

And the first thing that you mentioned was certain words or definitions that you think are maybe harmful or not accurate. And one of those was high performance. So I want to know if you can explain kind of why that word triggers you. Well, I think we just have to step back a little bit when we talk about. Almost any term. But high performance is a big one for me because right away it's put into a rubric or a barrel that it's only like top players.

So then you just start working backwards. Okay, if you're number one in the world, I'd say that's high performance. But wait, if you're number 50 in the world, are you not a high performer? I'd say that's pretty darn good. You're making a pretty good living. I mean, if you're top 100, are you not a high performer? If you're not top 1,000, now let's step back. If you're not a college player, D1 college player, are you not? I mean, you see, so now you take it back.

So there's high-performing players and there's helping players achieve the highest level of potential within their ability. That's high performance. It's helping people achieve what their potential is. But then think about marketing. Think about someone in a small community who... is an incredible networker who has a grassroots program that's through the roof. Are we not calling them a high performer? See, the coach. See, so I think there's, I understand the high performance player.

But again, you got to be careful because so a D1 player playing number four for a mid-major D1 school, you're saying that's not a high-performing athlete. It's pretty good. They're not going to make a living, but it's pretty good tennis. I mean, most of us can't beat that level of player. And it's funny because most people I've heard this, that you're not supposed to use the words good or bad because a lot of players will say, oh, that's a good player over there.

And I'm like, well, the people at Duke that I coach would have thought that was a bad player. The reality is it's the same player, right? So a three, five, the three, five. So yeah, exactly. So what is a good player? Like I actually think.

Alcaraz probably looks at someone who's 125 in the world and is like, you know, it's not going to be that much. He's going to go through his process, but he's not really threatened by that guy the same way he would be number five. But everyone else on the planet.

looks at number 125 as if they're this amazing unicorn, which I would kind of argue they are. So the words good and bad sometimes could be misused as well. I don't disagree at all. And I mean, let's use that example. Alcaraz knows how he's going to attack number 125 pretty easily. He knows, he can see where a lot of us, we see number 125. This player looks like formidable. I mean, but Alkares sees it and it's all relative.

It's all relative. And if you work with a college level, I know you work with college teams, you can work with how do you attack that opponent? I think one of the things that I've always loved about tennis, and I'm not the one that originated this phrase. But it's a game of emergencies. So your job as a tennis player is to create a bigger emergency for your opponent than your opponent creates for you.

So now can you go on defense? Yeah. Can you go from defense and then get back on offense? You know, I mean, players don't think like this. We start just putting things in a rubric and they're good. Well, let's just break that down a little bit. Can you give a specific example of one way that you could create an emergency for your opponent? Well, they come to the net and you hit a great lob.

You just created a heck of an emergency. And that's the easiest shot in the world to hit is a lob. I know some coaches that say, don't ever lob. And I'm going, you've got to be kidding me. It's one of the best shots in the game if you know how to use it. I mean, that's an emergency. You've got a tall player putting a ball on their feet, making them volley up. You're creating an emergency. So when you put a player into a situation that creates a little discomfort, that can create an emergency.

One thing that you are big on are laws, principles, and preferences. And you just kind of gave me a quick rundown before we started this, and I absolutely fell in love with it immediately. I hadn't heard it, actually. So I'm wondering if you can share those three words and kind of what they mean to you.

Yeah. So I've always been a big believer and, you know, here I am a scientist, you know, I'm a sports scientist in the game and. When I started doing this in biomechanics, a lot of people argued with me because they're traditionalists. I understand, you know, most people, most tennis coaches.

Until we really understood that there's a real art and science to coaching that they taught the way they were taught. And that's not necessarily wrong, but it's not necessarily the best for that player you're trying to help. So what I thought about as a biomechanist and as a sports scientist, the idea of laws, principles, and preferences. And I'll just give you an example. A law will not be violated.

Like Newton's laws of physics won't be violated. The law of inertia, a body will stay at rest or stay in motion until acted upon by an outside force. Now, a lot of people say, well, how's that related to tennis? Okay, you've got a 3.5 player, male or female. This is not... This is both genders, you know, and they look like this. The ball has been hit to my forehand. I probably should move. I think I should move now. Yet you look at the great mover and the ball is going to my forehand.

And it's like ready, pop, pop, ready, read, react, pop. And they overcome inertia very quickly. So they know how to overcome inertia. A lot of players don't. Then there's the law of acceleration. Force equals mass times acceleration. Mass is constant. So the more force you apply, the more you accelerate. But what we don't understand is the more you accelerate, the more force you have to accommodate.

So thus players that use poor technique and swing hard end up with arm and shoulder problems because their body's not able to accommodate that acceleration. Then the third law of motion I think is probably the most one that's violated. by tennis players, and that is that for every action, there's an equal and opposite reaction. And the best word picture I have is a two-handed backhand. The player starts to swing, and their back leg comes off the ground too soon, and they go into like a pinpoint.

Well, see, now, if the back foot comes off the ground after the ball's been hit, no problem whatsoever. But if it comes off during the forward swing, now you've changed the center of gravity. and you've changed the base of support. So now it's possible you're going to change the line of swing if you lift that back foot.

too early. And that's action and reaction, where the back foot is rotating around as the body's rotating one direction. So we see an action. Here's another one, action and reaction. You go up to serve, and as you go up... the opposite arm comes across the body to put a brake, B-R-A-K-E, on the rotation of the trunk. So this accelerates. That's action and reaction. So those are laws you're not going to violate. You just can't. That's the laws of physics.

Now, a principle, the most common, I mean, there's linear momentum and like if you cut a ball off, you've got more speed because you've got forward motion on the racket. But the one that I think is probably the best word pictures, it's called moment of inertia. And the best example. figure skater on the ice. When they're spinning very quickly, the arms are in, and all they do to slow down is lengthen the arms. So they increase the radius, so they slow down the rotation. In tennis,

You know, the old straight back backswing where the arm is way back. It's hard to rotate like that. That's like somebody like Jimmy Connors. When he was way back like this, he would leave the ground. when he used this kind of a swing, because he had to rotate like that. But a lot of players in today's world, they start with the elbow in a little bit more, so they rotate faster, and then they increase the lever arm to get more racket head speed.

That's where moment of inertia is used. Then, you see, this is where I think we've got to be really careful. Preferences. I hear so much criticism about how somebody teaches a certain thing. Well, that's their preference. If they're teaching it that way and they're using a cue and you might say, well, I don't like that cue. Well, maybe you don't, but maybe it's helping their student accomplish.

what we're trying to teach. I think we ought to be careful. So you can use a preference to teach and accomplish a goal. And that probably, it doesn't necessarily have to violate laws and principles to get the job done. preferences or teaching cues that help us help our students accomplish what they need to do. I want to take this time to thank ADV for sponsoring the podcast and my 2026 doubles camps. Not only is it a great backpack that's made my day-to-day as a player and a coach much easier.

But I've enjoyed sharing the bag with the players who attend my camps. And being the absolute legends that they are, they actually let my Indian Wells campers pick between their V3, V2, and Flex backpacks for their gift bags. If you want to upgrade your current tennis bag or backpack, click on the link in the show notes for 10% off. So when you're looking at coaches like me who you now see primarily online or just coaches across the country, across the world.

you would say that we should all be aligned on laws, clearly principles for sure. But then we would all have our unique style and preferences. And that's where you would say, Hey, every coach has the leeway to be an individual and kind of go about that the way, as long as we're all getting to that same spot.

100%. 100%. I think we've all got, well, take learners, for example. Learners, auditory, visual, kinesthetic. I mean, there's three different ways. There's three different ways people learn. So you can't teach them the very same way. You've got an auditory learner. Explain what's going on. I'm often asked, you know, as being a scientist, how much should we explain to students? Depends on your student. If you've got a student that's analytical as heck.

Go ahead, give them the information. You just don't want a paralysis by analysis. You just don't want them overthinking too much. But if they want the detail, give it to them. But then the visual learner, you've got to demonstrate. You've got to say...

I want you to see what I'm doing. Then the kinesthetic learner, you might get in front of them, visualize, but then have them model it with you so they feel what's happening. So there's three different ways of explaining possibly the very same thing. We mentioned that, you know, you do follow stuff online and now you see so much information, whether it's YouTube, Instagram, just anywhere, basically on the internet and you have.

three, five players, players who maybe aren't as fully educated in the game as you are, for example, how will they know when they're consuming information that is actually violating a law you're getting information it's not a preference it's actually someone saying something that is factually incorrect but you are a novice so you don't have the skills to maybe judge that how can

How can they navigate that? Because there's going to be a lot of learning that's done through YouTube, through AI, through the internet moving forward. And you want to make sure people are getting that correct information. Well, that's a tough one because there's no regulation. I mean, somebody can say anything they want.

And... I would always have a trusted resource. I mean, I'll tell you, I've already told you, the ladies that I coach, they send me your doggone Instagrams and YouTubes, and they're going, what do you think about this? Do you agree with this? And I always do. I mean, you do a great job. But you have to have a trusted resource, I believe, that don't take everything as gospel because there's some stuff that's being said out there that's just incorrect.

And not only is it incorrect scientifically, it's incorrect artistically to achieve the end that they're trying to achieve. Like they're saying things that just aren't biomechanically or even psychologically correct. So you have to have a trusted resource. But I'll vouch for you. I will. I love that. I want to talk about your three C's and how it relates to what we were just talking about. So real quickly, can you share those three C's with the listeners out there?

Well, there's credibility, there's conscientious, I mean, there's, you know, the three, you know... Do you hear me do that with Emma? Is that who you heard me do that with? I've heard it on a couple of your podcasts. The idea of being credible and doing the work, do the work, be conscientious and be diligent. You know, the credibility, conscientious, you know, cohesive, bring people together. I mean, I could come up with even more than three C's. I mean, it's just so key to...

being who you need to be. Remember, coaching is an incredible opportunity, and it's an incredible responsibility. You are influencing people's lives. This is not... You need to be conscientious to teach the right thing. This isn't about getting clicks. This is about doing the right thing for people and helping people. The internet can be great or it can be awful.

because there's no regulation. So be conscientious in making sure that you're teaching as a coach, and as a coach, you're teaching the right way. As a student, you're learning the right way for you. Maybe have a resource that you want to ask, you know, like my ladies do with you, with me. I mean, maybe there's another coach. You say, what do you think about this? Or a friend who studies the game.

What do you think about this? I just think there's more that we have to do. The credibility piece, I mean, I'm a big believer in certification. I'm a big believer in continuous learning. I mean, I've never stopped learning. I mean, in my book that I've got coming out, I talk about having a childlike curiosity. I mean, here I am at my age in life, and I still have a very, my son calls me immature, you know, and I'm fine with that, you know, because.

I want to be childlike. I want to be, I don't want to stop. I don't want to be an old man. I mean, I am an old man, but I don't want to be an old man. You know what I'm saying? I've heard you talk before about a coach being a good listener, right? The difficult, well, I actually want your feedback or advice for me because when I'm throwing something out on Instagram or YouTube.

I'm not, I mean, I do try to listen to comments. I read the comments. I can see how a post is doing, but a lot of times that's algorithm based and hook based. And did I put the right thumbnail out there? I don't know that it's necessarily the content. So it's kind of a one-sided conversation. Like those ladies you're mentioning in Florida.

I've never met them. I don't know anything about them. No, they love you. Right. So I don't know who sees my stuff. So I feel like I'm just given this one way. Hey, I'm just out there preaching and saying whatever I want. And it's a very weird coaching relationship. So I actually want to know how you think someone like me can navigate that because listening is such a huge part of coaching. And yet in this online world, it seems very one-sided.

Well, we just met for the first time, but you come across as a very curious person. You don't come across as dogmatic, rigid. I think you come across as someone who wants to keep learning, too. And I think that's... For me, if anyone ever thinks, all right, I'm going to say something that's going to sound a little egotistical. I mean, I've earned my way to maybe be...

pretty firm and rigid in how I teach, but I'm not. But I'm not. You see what I'm getting at? I'm very curious. When someone disagrees with me, I say, okay, help me understand that. Like the ladies will send me somebody else's tip and I might say something like, I don't agree with how this is being explained. Or I'll say... wow, I'd never thought of it that way. I'm very open. Here I am in my position to saying I'd never thought of it that way. I like this approach. Let's try this on the court.

That's my approach with my ladies. So I might see something and they might find it interesting and I'll say, and I'll push back if I agree, but if I go, or if I don't agree, but if I think it's interesting, I'll say, let's try this tomorrow when we're hitting and we'll give it a shot.

And we'll see if it helps learning. So I think we're always a laboratory, Jonathan. And that's how you come across to me. Everything we do is a living laboratory. Here I am as a scientist. I'm not rigid. Great science. All great science does is ask better questions. Great science isn't definitive, and great science isn't dogmatic. Great science asks better questions.

So as a sports scientist and someone who's constantly curious and trying to learn, is there anything, I guess, what is the most recent example of something that you've learned recently? where you're like, you know what, I always kind of thought this way, but you know what, science or the new information that's out there has made me kind of reconsider that old belief from maybe 20, 30 years ago. Well, I think the best word picture is some of the new teaching aids that are coming out.

Like some of the new teaching aids that are out there to help, like on the surf, for example, we always all use the old long sock with the ball to get that delay, but there was almost too much of a delay, and now there's some teaching aids that make that delay not as fast, and I'm going, like that so I'll buy something like that and I'll try it with my ladies. There's some stuff out there that works on movement and helps people lower their center of gravity to help their movement.

I'm willing to try things like that because in principle, it looks like it could work. But then I want to see – then I want to test it and see does this seem to accomplish what I think it can. That's my approach. Yeah, I love that. You're basically in every Hall of Fame. When I was looking you up, you have...

a thousand letters behind your name for all the things that you've learned and accomplished in every hall of fame. And you have all these areas of the game that I've heard you speak about. I've read about where you've got nutrition. You said you're a biomechanist. You've got the strategy, you're on court stuff. Is there an area of the game that you find to be the most powerful or most important for just the everyday player out there? For the everyday player, it's so simple. It's so simple.

The majority of points are won on errors. If you can just minimize your errors, you're going to win more matches. It's so simple. It's so simple. I mean, hit every ball deep into the middle of the court. And it's boring. You know, I love to say to my ladies, they'll hit a great ball and I'll say that sells tickets, but it doesn't win matches. You know, people love it and it feels great and people love to see it. But what wins matches is not missing.

And to point, just last week, I went up, my ladies were doing, they were playing some practice matches in a drill group with some of the other pros, and I know them all, so I know the pros, and they welcome me out. So I'm watching them, and they played three games.

And then the pro said, Jack, do you have anything you'd like to say to the ladies? I said, yeah. I just watched you play three games. How many winners were hit in those three games? One, Jonathan. One winner was hit in three games. Everything else was a mistake.

It was an error. And I'm going, ladies, minimize the errors. Get the dang ball. Yeah, the opponent might hit a great ball. If you hit a ball, you poop a ball in the middle of the court, they might hit a winner off that ball. It's just one point. I have a theory about, I think players are more afraid of their opponent hitting a winner than they are of themselves missing the shot. 100%.

Yeah, so when they're in trouble, like you just said, there's one winner for three games. You can say, hey, I can show you evidence that this almost never happens, that your opponent is going to hit, let's say in a two out of three set match, 15 to 20 winners maximum.

And you go, so what's going to happen on all the other points? That's if they have a great day, by the way. So you're so afraid of one of those 15 that you would rather cough up 40 errors of your own because you don't want them to ever attack you, which seems so backwards to me. So what do you think? The information is out there. I think a lot of people have heard what we're saying about being consistent, and yet players still will overhit on defense and be so worried about those winners.

Well, this goes so far back. I mean, I wrote High Tech Tennis in 1994, and that's the tennis book that I'm probably most well-known for. And in that, I put statistics, and I remember the match very clearly. It was the NCAA finals, and John McEnroe had, and it had been played like 10 years before, but it was playing John Sodry.

And McEnroe won in very close five sets. They played three out of five then. But it was only one or two points separated the whole match. But Sadre hit more errors than McEnroe did. And it was a match that 100% was won on not hitting as many errors. Now, they're banging the ball. Let's understand. They're banging the ball. It's great. That's why we have spectators watching the game at that level.

For most players watching us right now to understand that a match is won on minimizing errors, you've got to ask yourself, what do I care more about? Do I want to hit winners or do I want to win matches? Because if you want to hit winners, you're going to make more errors. That's just the way the game is. If you're going to try to hit screamers.

Is it the same psychological principle as players or people who just say, hey, I want to get in great shape. I want to lose weight. And you go, the answer is really boring. You exercise a lot and you eat the right amount of food and you eat the right types of foods.

And you're guaranteed to lose that weight. And you go, but that's not very fun. I don't enjoy that, right? And so people will eat pizza or burgers or candy at night, sweets, and they don't lose the weight. Is that a similar psychological phenomenon of...

you know, that player saying, I want to win matches, but then they go out and they go, but I also want to just do it with winners. And you're like, well, it doesn't really work that way. No, there's two things. One, I want to, I'm going to come back to the mountain.

I want to come back to the mountain in one step at a time. That's what I want you to remind me of. But a lot of players, most common question I've gotten in my decades of doing this is, how is it possible psychologically that somebody under pressure... like four all in the third or break point can hit a screaming backhand down the line for a complete winner. You know what my answer is? They're not afraid to lose.

Show me a good tennis player who's not afraid to lose. It's a very dangerous tennis player. Now, and you're talking about people that have an incredible hunger to win, but they're not afraid to lose. And if you're not afraid to lose, then you'll get balls back all the time. This is the pusher. The pusher just says, I don't want to lose. And I'm not hitting the ball hard. So I'm just going to start pooping the ball back. And suddenly you start choking. Oh, this is working.

You know, it was back in the day. I'll never forget this. Vic Braden pointed this out. It was so funny how he did it. Such a wonderful human being, Vic was. He was one of my main mentors in getting into the game. And Vic would talk about Americans playing other countries like Europeans and South Americans on clay. And it was just hilarious because you look at the data and he was right.

They start salivating. They see an American in the draw because they know all they have to do is keep them out there. And I'm not criticizing. We've got great tennis players, but the patience level isn't at the same level. as the the european i mean look look at if you look at the mid we did this data when i was the chairman of the sports science committee if you look at from 19 like the late 80s through the early 2000s

mid-1990s, and you look at all the American champions of like the U.S. Open, they were almost all second-generation Americans. Before Venus and Serena, they were all, almost all, I mean, think about Agassi, Sampras, Capriati, you know, all of them. Jim Currier was not. Jim Currier wasn't. He was a first-generation American. But they were also...

So what is it that makes that? If you talk to them about their family and their upbringing, they were hungry and they were patient and they were willing to stay out however long it took. And that's something that's ingrained psychologically. In a person. And I'm not belittling the United States. I'm not. Because I do believe that we have great tennis players. But there's also this ability to say, I'm willing to stay out here as long as it takes. And that's a different...

sort of a, you don't teach that. I don't know if you teach that. Now, now coming back to what you talked about, like just like simply losing weight or something like that. When we got on day two on the mountain, we were on the mountain for eight days. And when we were on day two, we were at about 12,000 feet. Now this is 19341. So we were still had 7,000 vertical feet to go. And the clouds cleared and we saw the peak. And I went, you got to be effing kidding me.

There's no way. There's no way. The self-talk went in the hole. I'm going, I got artificial knees. My son's 12. There's no way we can do this. So even my self-talk went in the pits. But I will tell you that I gathered myself, I got with my son, and the Chinese proverb, my son's from China, we said, you know...

The journey of a thousand miles begins with the first step. And then the next step. I said, if I look at that mountain, I cannot make it, but I can take the next step. And that's, I think, true in tennis, too. It's a very hard sport to master.

But maybe today you can hit a better backhand or forehand down the line. Maybe today you can work on getting a little bit lower on your volleys. Maybe today you can work on hitting the ball straight out from the racket and not hitting down so short into the court. Very simple things. One step, one step, that, and then just take one step at a time. Yeah, it's going to take a while. I've had people that say, gosh, I've been doing this for a year. Well, welcome to the game.

I mean, some people, they're playing 20 years later and they finally get it. So one year isn't that long. I'd like to transition to the book you just came out with, your most recent book, which is some of the stuff you've been speaking about climbing the mountain. Can you just let the listeners know what that book is about, kind of where it came from?

Yeah, this is it. It releases on January the 8th. It's called Mountains Within, A Life of Achievement, A Quest for Meaning, and The Mountain That Changed Everything. And what the book is, it's my life memoir, but it goes through everything. It's a very dramatic. It has all the cool stuff, all the science that I did in tennis and with the White Sox and all the speaking tour with Margaret Thatcher and Mikhail Gorbachev and Muhammad Ali. It has all the cool stuff.

But it also has the drama of my life with how I was driven, my relationship with my father, and then have struggles in marriages and marriages, plural. And so it was the struggles combined with all the... the really cool things to talk about redemption and transformation in one's life. And that's what I decided to write the whole story when I was on Kilimanjaro.

Wow. So you were up on the mountain and you decided that was when you were going to come out with the book. I said, I got, no, I was, you got to understand people were. It's just like in tennis. People hear, you're such a good player. I don't understand why you're winning. See, we listen to all this stuff coming into our brain. So everybody kept telling me for years, Jonathan, because I'd done all this really cool stuff. I needed to tell my story. But all they were talking about...

was the really cool stuff. And it was on Kilimanjaro that I realized there was exhilaration and terror at the same time. If I make a slip, it's 150 feet straight down on a cliff. I mean, in the introduction, I tell the story that it was a very cloudy, misty day, and it rained all night, and we're at a place on what's called Barranco Wall. It's 900 feet straight up, and you scramble. You don't have to have ropes or anything, but you scramble.

And we get to a point, it's called Kissing Rock, where the guide says, put your left foot on the ledge. It's about this big. And I said, I don't see the ledge. He said, it's under the mud. And you understand, it's 150 feet straight down. And he says, hold on to this rocky outcropping with your left hand. Put your left foot on the ledge and swing around. I'll catch you. And I said, you better freaking catch me. And I put everything in him.

my trust in him and swung around and he caught me. But the point is that the exhilaration and yet the terror and the anxiety and yet the euphoria. and then accomplishing the goal of making it. I said, this is exactly how my life's been. So if I write the memoir, it's got to be the whole story and the transformation.

Were there any side benefits or any self-actualizations that as you were putting this down on paper, obviously you know those events and you know those personal moments in your life, but actually being able to share that with everyone, was there like a side benefit or something that came out of writing that?

Well, I hit rock bottom emotionally when it wasn't expected. In 1996, I had to have a knee operation. The arthritis in my knees had gotten so bad. I had a knee operation and I contracted a staph infection. So I was hospital. I had a PICC line into my heart. They couldn't find the antibiotic to solve the bacteria. And I was in the hospital for 15 days. And I got phone calls, but I only had one person outside my family come to visit me. And I said, what the hell?

I said, this is not how I want to live my life. You know, I'm well known. I mean, I'm traveling all over the world and yet nobody's coming to visit me. And I realized innately that I wasn't investing energy in other people. I was doing a lot for tennis and for associations and for NGOs. And, you know, I'm just doing a lot, but I wasn't giving energy to people. And I said, this is changing.

And I got on a path, and I'll just do the net-net. 25 years later, when I moved here to Florida, I was hospitalized. a little less than two years ago with an atrial flutter that i think was artificially induced but it was an atrial flutter nonetheless and because i'd been volunteering to work with people and i'd been out of going out of my way and i'd made this transformation

Jonathan, I was surrounded by people in the hospital. And I broke out in tears when the realization hit me that I'd gone in 25 years from no one to being surrounded. by people that I could call friends. And it was all because I learned to invest energy in other people. That's fantastic. You mentioned earlier that you're a curious person and I am as well. And you said that you still work with 3.5 and 4.0 ladies. I do. Every day. I'm curious what you're working on with them lately.

Right now, what we're doing, we're playing pseudo points where I'll get with two of them at a time.

I'll play on the deuce side, and they'll be in their doubles formation, and then I can dink and move the ball around and lob, and they're working on communication and switching and when to close, when not to close. We literally did that the last two days. That's what I'm doing with different team members. Do you have any rules? People ask me a lot of times about how you communicate with your partner, especially in those situations. You lob a lady up the line. They've got to switch.

One thing I've always said is I don't know that there are rules because every single situation is different. The one thing I have said is the person on the baseline can at least see the net player. Yeah, the person in back controls the court. They control the person in back sees the whole court. So if the net person crosses, the person in back calls the switch because they see the whole court. That's always been my kind of rule. I love that.

Now, I'm going to try to pry a second one away from you. You said, obviously, the game is about reducing errors, which is absolutely scientific fact. What is your best advice for the 4-0 adult player out there? And you cannot use that same one that you gave us earlier. Is it doubles? It could be either. It could be doubles or singles. Or you can give us one of both. The middle is an okay place to hit the ball.

You know, I mean, middle's where the points are won in doubles. People don't realize that. They think they've got to play angles all the time when, in fact, the middle is where points are won. You set up the court. The court is geometry. That's probably the one thing.

Understand that a tennis court and playing a tennis match is geometry. If the person goes here, then you move in that direction. And then the court opens up where? And then the other thing is that I would share is it's easier to hit the ball right back where it came from. You know, when everybody tries to change direction all the time, it's easier shot to hit the ball right back where it came from and then play the point out from there, wait.

for your opening. I'll just give you a couple more. I've always said this. There's money shots and shots you cash in on. A money shot is a ball that sets up the point. Money shot isn't one you finish the point on. A money shot might be a really good approach shot. It might be a high loopy ball, but then you come in or you get a short response. Now you cash in on it and you finish the point. So I think that's another way of thinking about setting up a point.

using geometry, play to the middle, and then have money shots and shots you cash in on. You know what's funny is I had a girl, she's done great. She's at Michigan. She's a junior. This year, I think she was ranked number three in the fall.

She's gone to Michigan. She's taken off. She's been awesome. And she's got all these skills. She could come to the net. She had a great serve, great drop shot. And I was guilty of coaching her. And I was trying to do all these things with her because she had so many skills.

And she was doing well, but not maybe what we thought her potential was. And the last summer, I was just kind of like burned out. I didn't know what I was doing. I said, you know what? We're just going to get you in shape. And I want you to hit every ball cross court.

Let's just try it for four weeks. Let's just see what happens. And kind of what you were saying about the ball going back to where it was, she actually hit more winners because when she hit the ball early, she was going behind players and they were running open court. So not only was she being more consistent, it was a little accident on our part.

But I have found that people, when you say that, go back to where it came from. I think people think that's going to be pushing or not offensive. And I actually found sometimes it could be more offensive. 100%. You hit that ball right back where it came from. You've got pace. You've got direction.

and often they're trying to overthink your opponent is, and you hit it right back where it came from, they're surprised. And then you can hit with pace, too, because you're not trying to change direction of the ball.

I could talk to you for hours and I may try to get you back on at some point later in the year. I'd love to. I really do. I would love to do this. Yeah, I could do it all day, but I usually keep my podcast relatively short. So I will put the link for the book in the show notes of YouTube.

Thank you. Exactly. I'm going to get that myself. I could learn from you all day. Hopefully I'll get another chance in the future, but thanks so much. I'd love that. I enjoy your work. Congratulations to you and everything you're doing. You're doing a great job. Keep it up.

All right, I want to thank Jack for joining the show today. He's forgotten more than I'll ever know, but I love his thoughts on laws, principles, and preferences. Every coach, including me, teaches things a slightly different way. We might have a unique phrase or a visual that we like to share.

but we all have the same laws. So make sure when you're consuming content online or through a podcast, you're trusting coaches who are teaching biomechanical facts. As always, thanks again for listening. I hope you just improved at tennis without even hitting a ball.