Hawk-Eye Live: Sam Green on the future of officiating aids in tennis and beyond

Among a host of other experiments, November’s inaugural ATP Next Gen Finals saw the successful debut of the Hawk-Eye Live automated line calling system. Hawk-Eye Innovations head of tennis Sam Green discussess the inner workings of the system, its roots in soccer, and the future of refereeing aids.

Hawk-Eye Live: Sam Green on the future of officiating aids in tennis and beyond

For almost two decades, Hawk-Eye Innovations has become an ever more integral part of a widening range of sports. Since adapting missile-tracking technology for cricket on television at the turn of the century, it has gone on to provide pioneering refereeing aids in over 20 sports.

It has been at the core of the decision review system in elite tennis since its introduction in 2006, allowing players to challenge line calls at Grand Slam events and other top tournaments across both the men’s and women’s tours, including the ongoing ATP Finals at the O2 in London. Earlier this month, the company executed one of its most ambitious briefs to date when it rolled out its Hawk-Eye Live service to replace line judges altogether at the inaugural ATP Next Gen tournament in Milan.

SportsPro caught up at the Italian city’s Fieramilano convention centre with Sam Green, the Hawk-Eye director of tennis, to talk about how the system came into being and how knowledge-sharing and forward-thinking are more important than ever in an era when more and more sporting bodies aim to eliminate officiating errors.


SportsPro: What’s the history of the Hawk-Eye Live system? At what point did you start working on a product like this?

SG: It was the end of 2016 when the ATP spoke to us about the possibility of doing line calling in a live way. Initially, we tested at the O2 - a blind test at the World Tour Finals. The system then had a few things that we needed to work on. We moved to Indian Wells where we did another test, where actually Tommy Haas and Mardy Fish were involved in hitting. It was great to get feedback from ex-players - or current players with Tommy Haas - and see what we needed to work on.

The main issue was the speed at which the decisions were being made.

We then had our final test at Cincinnati where the system came together and after that test, the approval came from the ATP.

Was that capability something you’d been working on internally?

It was kind of a byproduct of some other things we’d been doing. The way the Live system works is very similar to what we do in football with goal-line technology. So it was making sure that that technology worked with the way that we track tennis balls, and the way the tennis system worked.

It wasn’t so much starting a system from scratch as adapting a current system.

At what point did you start thinking about this tournament and when you needed to be ready for it?

We had some time after the tournament was announced. The testing that I mentioned at Indian Wells, following that we knew that Cincinnati would be the make-or-break test as to whether or not the system was up to scratch for the Next Gen Finals. We knew that during testing at Cincinnati, we had to make sure that George Ciz and Gail Bradshaw and Ross Hutchins were happy with how the system was working and it was a couple of weeks following that test that the system got approved for this tournament.

So that’s the point where we really ramped up and made sure that everything, in terms of the integration with the LED digiboards and the big screen replays, the whole system came together to make sure that it was a full picture rather than just the line calling.

Is it a software or hardware change to get it from the review system to this live calling model? What’s changed between the two systems?

The hardware is very similar. There’s just some additional hardware for redundancy purposes to make sure that if there is an issue with a piece of equipment, the system will continue to work.

The biggest changes are from a software perspective. It’s making sure that the way that we track the ball continues to be the same but everything is done in real time, which has implications from a wider perspective in terms of data and data delivery, but mainly that all the cameras are brought together as it happens, within 0.1 seconds.

The key thing is that it feels right for the players, and for the officials, and for the crowd.

How much did you work with the ATP on the aesthetics and the way that it fits into the game? Because it obviously plays a very different role now, where you effectively have a robocall. How much of a conversation did you have with them about how that needed to work?

Yeah, there was a lot of conversation and consultation. We would provide examples of what we could do and then there would be discussions with ATP, and that would be refined so that the overall look and feel was right for the game. We’re not the ones who want to force this upon tennis or the way that it looks.

The idea was that it felt part of the natural show and at the Next Gen Finals here there’s obviously a lot going on with the big screen and the digiboards, and it was really important to ATP and ourselves that we integrated well. So there was a lot of close work between us and ATP to make sure that everything looked as we wanted.

It’s notable as well that you’ve been quite conservative with the voice that you’ve used for the line judge, for example. Is that an accommodation you’ve made with the players? How did you come to that decision in terms of how it would interact with what was going on with the game on the court?

During the testing we tried a considerable amount of different options. We tried the likes of a beep or a buzzer, something that’s more electronic, but it just felt right with a human voice. And I think a lot of this is how it feels, rather than the technology which we know is doing its job. The key thing is that it feels right for the players, and for the officials, and for the crowd. So that’s where the human voice came into things.

What have your preparations been like for this week specifically? Getting cameras set up, getting your hardware set up and plugged into everything that it needs to be.

It’s been very similar to a normal event for us. We make sure that everything’s configured before we arrive at the venue, and then it’s a case of making sure that all the cables are run in as per normal and the cameras are put up around the stadium. So really it’s a few days of manual work getting things ready and then calibrating the system, and then making sure that we’re testing with the third parties and with the ATP to make sure that everyone’s happy with the overall system.

The use of the Hawk-Eye Live system meant there were no line judges in place at the inaugural ATP Next Gen Finals in Milan

How’s the feedback going to work from this? What are you looking for out of this first live run?

I think the key things are looking at how it feels for the players and how it feels for the officials and the crowd, to make sure that we can improve the overall product. We’re always looking to improve what we do, and as we consult with the ATP and we consult with various stakeholders to make sure that it works for broadcast and it works for all parties.

Out of this event, we’d like to get those iterations correct and look to implement the system on a wider scale across tennis.

How receptive do you think not just the ATP but others involved in tennis - particularly the players and the broadcasters - would be about that change to an automated system?

I think from a players’ perspective, we think that we’re delivering a system which is going to help them because they’re getting the most accurate calls all the time. So rather than disagreeing with a line judge’s decision and then looking to challenge and therefore get the correct call, as per the technology, they’re getting that every time. It takes away the concern from the players as to whether or not they need to challenge, whether or not they should conserve challenges because they’re not sure, and allows them to concentrate on just playing the game.

From a broadcast perspective, we still create the same data and we can still add to the analytics side of things, whilst also displaying those line calls where people are not sure how close it is.

You mentioned the relationship between the update to this product and the goal-line technology that you’ve been supplying in football over the last couple of years. How much are you learning from different systems and how much can you apply it across all of them?

As we do a lot of sports now – we officiate in over 20 sports around the world – and we learn lessons from each sport. So there’s a lot of crossover with technology now in terms of how the Live system comes together, for example, with GLT. But the things we learned through the development - and it was a long process, working with Fifa to get that system where it needed to be - we learned the lessons from that and brought that across to tennis. So we feel that we’re not starting from scratch - it really is an iteration of the tennis systems and the other systems that use live tracking.

This is what we feel was right for tennis and we learned the lessons from the live system in football and made those changes.

Is that development always something that’s coming from the rights holder side? Are they coming to you with demands based on what they’ve seen in other sports or are you going to them with what’s possible?  

I think it’s more that we see things that we’ve done internally and that we can develop systems from that perspective. For Hawk-Eye Live, what we’ve done is taken a request from ATP and a conversation about live line calling, and we’ve learned our own internal lessons from GLT. So it wasn’t so much that ATP looked at football and said, ‘That’s live - can we do that?’ It was more that this is what we feel was right for tennis and we learned the lessons from the live system in football and made those changes.

What other examples are you able to share of that kind of thing happening?

We have video replay officiating across a lot of sports. For example, in Australia there’s been a lot in NRL, AFL, and throughout world rugby we’re doing video replay officiating. And with the recent addition of VAR in football, the lessons that we’ve learned across the different sports where we’ve done video replay officiating have been brought into that system. So I’d say that that’s one where we’ve built on the product that we already have and then tailored it more towards the football system and the client that we have in that case.

What’s the future for the Hawk-Eye Live product and also for Hawk-Eye more generally? What are the next steps for you?

I think the next steps are really to look to broadly use this product across the tours, and it’s not just main courts where we currently officiate but really looking to try and officiate across events. So for example, at Indian Wells we’re present on every court at the moment but that’s the only event where we officiate on every single court. I think that’s where the system can really help with the growth of Hawk-Eye in tennis, across all courts on all tours.