Marc Sophoulis
Thanks for joining us again here on Crunching the Numbers with Shane Liyanage and Marc Sophoulis. We are here once again to dissect the game of tennis. And thanks again for joining us Shane.
Shane Liyanage
Thanks. Hi everyone.
Marc Sophoulis
Look, I think we discussed a lot based around the winning ratios of the best players. We spoke a little bit about how Rafael Nadal was obviously the prime example, winning probably 54%, 55% of points on the clay courts. Being so dominant on clay, we expected him to have a high ratio. He doesn't. And I think it's to be expected that we are going to lose almost half the points that we do play Shane. So I think looking back on that, that was probably one of our key points. The other one was the winning the zero to four rallies. I think that was another big point we did speak about. What was a percentage of points that finish with fore shots?
Shane Liyanage
Well, I think the average rally is about 4.4 shots and I think it was around 70%.
Marc Sophoulis
70% of points finish within four shots, so hopefully you've been able to go away this week and practice the start of the point where the serve and return become very crucial. And also playing to your strengths. So we did speak about Nadal and those big moments he does play to his strengths in terms of his big serve out wide to the right handers backhand and then follow it with a forehand. So hopefully as a listener out there you've been able to take something from our first episode of Crunching the Numbers. Today's a little bit different. We're going to talk a little bit about something that not many people will have heard before or spoken about or maybe even coached, and that is shot chains. So can you explain to us Shane, with your data hat on, what shot chains mean to the average person?
Shane Liyanage
There's probably a couple of ways to define it, but the way I define it is it's shots hit in a row by a player. So this excludes what the opponent hits. So for instance, a shot chain of three after your serve could be forehand crosscourt, forehand down the middle, forehand down the line. At this stage, we're just looking at your own shots. And in terms of why I like to limit it to two or three shots when you analyze a shot chain is the average rally, as we talked about, is 4.4. So you don't want to look at a shot chain that's longer than that.
Marc Sophoulis
So to me, as a coach listening to that explanation, why is it important for me as a coach to know or if you're a player out there or a parent listening to this podcast, why is it important to that person that's out there on the court?
Shane Liyanage
We talk about taking advantage early in the rallies and the big players are doing a lot of damage to their opponents early in the rally. So in a shot chain, you want to maximize the shots early in that shot chain that are going to give you the greatest reward. And we go back to that first week, that 53% of points won. It's not a big difference between the top and the bottom. So any little thing that you can do to try and get your best shots out there is significant.
Marc Sophoulis
And I guess that's probably the biggest thing under pressure is that when we get to pressurised situations and we're standing up on the line ready to serve, if we know our best shot chains, it probably lifts our probability of winning that point. I know you've done that with my players as well, is said to me "these are the kind of sequences that they need to utilize under pressure". So have you got anyone in particular in mind that you have, I guess an example of that might use a certain shot chain?
Shane Liyanage
I do, I might actually jump into a story. Last year, I worked with a particular coach and player and they were actually disagreeing in terms of what they thought their best shot pattern was. The player had a certain view and then the coach had a view. And I came into this tiebreak with the data and presented it back to them. It turned out the coach actually had the 4th best option and the player had the 18th best option. So that in itself was quite interesting.
Marc Sophoulis
I think that's an interesting fact, I always have discussions with the players around what I think is best. But the coach only has the eyes. And I think this is the big thing that we spoke about last week was the data gives us the fact. Now a coach can have an opinion and have the eyes and say, this is what I'm seeing. But data gives you the pure fact. And I think when you're dealing with people's opinions, they're going to differ a lot of the time, and especially if you clash from a personality perspective. I think what you're talking about here is that you've given them the facts behind what is actually happening. And they're just trying to guess at the end of the day.
Shane Liyanage
Absolutely. It worked out really well, we looked at the vision after that. They had a block after the French Open and Wimbledon where they trained some of the new information, the patterns. And they had a lot of success on the grass following that. But going back to your original question, I had a look at Serena Williams, Novak Djokovic and Rafael Nadal in terms of how on break points or under pressure, what patterns they play, and they will alternate between their top five shot chains of three. So they'll revert back to their strengths under pressure.
Marc Sophoulis
So Nadal, would he be using the serve wide and utilizing the forehand as many times as he possibly can early in the rally?
Shane Liyanage
Yeah, absolutely. And that's not just on the clay, even on the hard court and on grass. He does like to go to that pattern. I've noticed in recent years, he's actually using the forehand up the line on the quicker surfaces a bit more with the second shot in the rally. But yeah, I think under pressure, he does like to use the serve out wide.
Marc Sophoulis
I think that up the line shot (and this is obviously for that tennis lover out there watching Nadal play), he generally plays his forehand up the line to enable him to get to the other side of the court and use his forehand from his backhand corner, if that makes sense. I think that's important because it's obviously his weapon and that's where he plays his best tennis from is in his backhand corner. We talked about Djokovic. I reckon this might be an interesting one. I hope you can answer this one. Djokovic's patterns - It looks like he's backhand is never going to break down, it's his strength, it's something that he never misses. But I'm guessing that being a male player, he's going to utilize his forehand as much as possible still.
Shane Liyanage
Yeah, absolutely. So while his backhand is an incredible shield and it can withstand a lot of pressure from opponents, I think Djokovic plays even better when he can use his off-forehand and even the inside in forehand, purely because I think bio-mechanically, the forehand can still generate a bit more power.
Marc Sophoulis
Yeah, that's right. From a bio-mechanics perspective, the actual rotation that you can get on a forehand compared to a double handed backhand is about 10 per cent more rotation, which means a little bit more elastic energy built up. And from elastic energy we build a lot more power and force. So definitely the forehand would generate more speed. I'm interested to know about Serena. Obviously, you brought up Serena as someone as well that you've looked at. What would be the difference between the male and female patterns of play and what's Serena's patterns on that first 3 or 4 shots in terms of her shot chains?
Shane Liyanage
She can go big with the forehand and backhand. In particular on her serve, she'll use the forehand early in the shot chain. On the return sometimes you don't get the choice really on that first ball. So you can see that some of our shot chains start well with her backhand. But the driving volley is also something that she often gets on that third shot in the shot chain.
Marc Sophoulis
Why does that happen? We talk about drive volleys in the female game. What do you think Serena is able to get that on the third or fourth shot so comfortably compared to other female competitors?
Shane Liyanage
Look, I think she just hits the ball harder than most of the tour. A lot of the girls are now hitting a lot harder as well. But she also takes it a bit early. So the time's taken away from the opponent, so she can move forward as well because she's never starting that deep.
Marc Sophoulis
What else have you got in terms of our numbers for this week Shane?
Shane Liyanage
It's interesting. I think I brought up a couple of players, but I didn't bring up Federer. One of the challenges of looking at Roger is he's very hard to predict. And being an all court player, he can use a lot of different patterns and still have success. Particularly in the last couple of years he does try and get to the net a bit more. So I've noticed a lot of the third shots in his chain are at the net. He's definitely the hardest to predict of all the big players.
Marc Sophoulis
So you're telling me the man with all the numbers, the man with all the data, the guy who thinks he knows everything about the numbers of the game, is telling me that you cannot predict what Roger Federer is going to do on the big points?
Shane Liyanage
He is incredibly difficult to predict. I think you can expect he wants to hit forehands early in the shot chain. Other than that, he's very clever in terms of how he can use his slice, he can dice you many ways.
Marc Sophoulis
I guess that looking from the outside in now, the coaches hat comes on here, is I look at athletes that we're developing. Anyone out there that's an athlete or a parent or a coach out there looking to develop someone - It's so important to have so many facets to your game that you can actually turn to the big moments so you're less predictable. Similar to what Ash Barty has been able to bring to the female game. And Roger Federer, obviously for so many years. It just makes such a difference when nobody knows what shot chain you're going to produce at any particular time.
Shane Liyanage
Yeah, absolutely. So I'll present the shot chain - what your best shot chain is compared to how often you use it. But another level analysis I put on it is predictability. So if a particular shot chain works well once, but if you continue using that shot chain, does your opponent start reading it? And that's a layer that you need to consider. So you can't use the same pattern over and over again and you want to be able to pick a shot pattern that's robust enough to use for the majority of your points.
Marc Sophoulis
Well, I'm going to challenge you on that, Shane. So I know you're the man behind all the numbers. But out on the court, one of the big things that I talk to players about is the ability to be able to have a certain pattern of play that they can turn to at any particular moment, regardless of whether the opponent can read it. As long as you can execute it well enough, the opponent still has to execute the pattern against you. Now, we're going to conflict here because you're going to tell me the numbers, but I'm going to look at it and say I do love the way Nadal plays. We know where he's going to hit the ball. We know how he's going to hit the ball. We know what he's going to try and do. But it's bloody hard to counter that.
Shane Liyanage
I actually think we're closer than you think.
Marc Sophoulis
Let's have a look.
Shane Liyanage
With the shot chain, there are certain patterns that are going to be successful, they might not be your best shot chain, but it's a shot chain that is successful and is robust. So this is where no matter how predictable it is, you're still going to have success. For Nadal on clay, that particular pattern that we're well aware of - you can't do anything. There's very few on the men's tour that can counter that. That's a robust pattern. There could be another pattern where it's up the line up the line, which might work once in a while, but it wouldn't be a robust pattern for him.
Marc Sophoulis
Yeah. Gotcha. All right. We can agree to disagree, but we can agree a little bit more than I think we can agree.
Shane Liyanage
That's right.
Marc Sophoulis
I think that's a really important point. How do players out there without the use of someone like yourself, for example, how is someone out there able to utilize shot chains when they don't really know the data behind what they're doing? How can they get the numbers to back up what they are thinking or feeling from an opinion perspective?
Shane Liyanage
Look, I think it's always important for a player to look at their own vision. So when you're on court, you might not be able to process everything. You're very reactive. But after the match, it's important to look at the vision and then you might be able to pick up and go, "ok you know, that shot was good". And then you go out and practice what you think is working well and then hopefully it becomes ingrained. I'm not aware of a lot of resources out there that do this.
Marc Sophoulis
I think that's a really challenging one, because you may give a player a shot pattern that might be successful for them, but they may not feel comfortable enough to do it. And that's the challenge I feel as the coach is being able to say to a player, "you know, your forehand cross into your forehand line, into you run-around forehand are your three best shot sequences that you utilize and you have a 70% chance of winning the point". And they tell me that their forehand is not their favourite shot. How do I then convince my athlete? Is it through pure numbers? Is it through showing vision and numbers? What do you think from your side of the fence?
Shane Liyanage
Look it's a combination. I think the numbers are one part of it, but sometimes you do need to visually see it in action to kind of get that buy-in. I go back to that early example with the player that we worked with. We had to show vision and we showed vision over and over of what he thought was his strength and vision of what the data showed. It took a bit of that for him to get that buy-in. And I think that's the same no matter what level your at.
Marc Sophoulis
I'm glad you said that. It's all about the buy-in and it's all about building that relationship with your athlete. From a coaching perspective, we need to be able to build that significantly before we even introduce things like this. But the other thing also is once you do identify those patterns, it's not just about going into the match and doing it. It's actually about practicing the patterns and enabling the player to practice it over and over again to make sure it's ingrained into what they need to do on the match day. There's no point going into a match and saying to them, you need these three shot chains and then they haven't practiced it previously, and then they're expected to go out there and execute.
Shane Liyanage
Yeah, absolutely. It's not just practice on court. It's physically being able to do it over and over again. So there's movement elements and stuff at the gym that you've got to do to be able to execute that pattern. So there's lots of it that go in and really want to shift the over use of patterns that are not successful and try and get players to play points with patterns that do bring success. So if you can try and learn your dominant shot chains, whether it's by watching video or getting some data, do that and then practice them until they're ingrained. And that means not only hitting on the court, but doing the physical work off the court. So you're able to play those patterns over and over again if you need to, for three, four hours. Obviously, we've just given you a taste of the analysis here. There are other layers to look at, like what an opponent might do, trying to predict the shots they'll hit in your response to your hits. You can actually take this analysis a lot further and we do it with certain athletes. For the data nerds, I use the rules and spader packages in the r-library. I think there's equivalent python packages in their library as well for sequence calculation. Now I might add a key part of this process for the analyst is to really work out with the coach the best way to present this information, whether it's a table, a court visual or drawing the shot chain out. In fact in recent times, I've actually got 3D VR tool that we use to show the shot chain with 360 degrees. So really work that out quite early on and then make sure it's something simple and the athlete can pick up straight away and doesn't have to dive in too much. Certainly, if you're interested in this kind of analysis, contact Data Driven Sports Analytics. It's also going to be a part of the strategic and data advice Marc and I will be making available as part of The Tennis Menu.
Marc Sophoulis
Great. I appreciate you diving deep into these numbers around the shot chains. I think it's really important for people out there to listen and to learn. I think we want to make this a real learning kind of podcast as opposed to us just telling people stuff. I think it's important that we learn from it and we take as much as we can onto the court and we can practice as much as possible. Thanks so much again, Shane. I really appreciate it. Obviously, we're brought to you by The Tennis Menu. Look us up online and Data Driven Sports Analytics where Shane is. We're really excited to bring this to you, because I think this is a real hidden gem in the game of tennis. It's been in a lot of other sports for many years, and tennis is now diving in deep into the data protocols of the game. And we can really dissect the numbers to give you a better understanding of what tennis is actually looking like and going to look like moving forward. Thanks for your time Shane, and hopefully we can get next week's up and running and go again.
Shane Liyanage
Thanks everyone. Stay safe.