Marcus Daniell whips out his mobile phone and starts scrolling.
"I'm actually pretty meticulous about recording expenses."
Moments ago, the Kiwi doubles exponent became the last hometown hope standing at the ASB Classic, helping Austrian partner Philipp Oswald (2.01m) through to the semi-finals.
In two days, he will fall one step short of regaining a title he miraculously won in 2010 - an ATP Tour rookie, ranked in the 600s, handcuffed to a top-50 player desperate for matchplay before the Australian Open.
Ten years of hard knocks on the professional circuit has taught Daniell that being frugal with his money is as valuable a skill as a topspin backhand or overhead smash.
During last year's US Open, enigmatic Frenchman Gael Monfils was reported as complaining he would need fourth-round prizemoney just to break even on his stay in New York.
Later, he clarified that a Round-of-16 finish would actually yield a $100,000 profit, once expenses were extracted. Fortunately, the world No.13 progressed a stage further than that and was able to put food on his table for at least another week.
While Monfils is never likely to starve, his outburst succeeded in drawing attention to the plight of lower-ranked performers, for whom winning a couple of Grand Slam rounds could balance their books for an entire year.
In 2019, Daniell made finals at Brisbane - where he claimed his fourth career title - Budapest and Rosmalen, consolidating a doubles ranking inside the top 50 and earning US$191,117 (NZ$278,017) in prizemoney.
That's his best financial result ever, but represents a modest return for a professional sportsman after a decade of perfecting his craft.
And his actual profit margin takes a beating, when you begin counting the costs of touring the world with a racket.
The 30-year-old right-hander has career earnings of more than $US800,000 (NZ$1.16m), but he's probably only finished in the black for the past four years, maybe five.
"It's extremely expensive and the biggest cost, which is also an investment, is coaching," says Daniell, checking the spreadsheet on his phone.
But the deductions begin even before that…
Doubles winners at tournaments like the ASB Classic can earn about US$15,000 - singles winners receive US$90,000 - but a significant chunk of that will immediately go to the taxman.
"It can be anything from zero to more than 30 percent, depending on the country," says Daniell. "It can be brutal."
"You've got to pay the wage of an expert and cover all their expenses - flights, hotel rooms and food - so you're essentially more than doubling down, because you're not paying yourself a salary."
This year, Daniell and Oswald will invest heavily into coaching, hoping it will take their game to the next level.
Wellington-based Aussie Clint Packer was to guide the pair through the Auckland-Melbourne leg of their schedule, while Daniel's longtime coach - UK-based South African Dave Sammel - or Oswald's mentor - Joachim 'Yogi' Kretz - will travel with them the rest of the year.
"We'll have a coach with us for 20 weeks this year, so that's a significant expense, but it's key to us taking the next big step."
Many of the top players will also engage a specialist trainer, but Daniell prefers a do-it-yourself approach on the road.
"For doubles, the kind of training we're doing is knowable enough to do ourselves. I can't count how many trainers I've worked with over the years.
"I feel I have a good enough working knowledge of my body, especially with all the injuries I've had. In pre-seasons, I do a lot of work with a specific trainer and then I touch base with him, when I'm away."
While Daniell and Oswald will keep their travel party lean and mean, that group will swell when family and partners tag along for the ride.
Oswald's wife, Linda, recently produced a baby son - conveniently born a few days after his final tournament of last year - and both are in Auckland this week.
"That's another reality… if he wants to see his family, they will have to travel a lot."
Daniell hopes his New York-based girlfriend will also join them for some events, but that's another added expense to take on.
In 2019, Daniell played 28 tournaments in Australia, New Zealand, Mexico, USA, France, Spain, Hungary, Portugal, Switzerland, England, Netherlands, Canada, Indonesia, China, Japan, Russia, Austria.
That itinerary put him out of pocket $30,000, the next biggest expense after coaching.
"We have to book the vast majority of flights last minute, because we never know when we're going to be out of a tournament."
While players remain alive in a tournament, their hotel lodgings are covered by event organisers. If they exit early, they at least have the option of sharing a room, until they leave for the next event.
Daniell paid $5000 for extraneous accommodation last year, but a hidden cost is retaining a home base that's rarely used.
"Early in my career, I wondered why I was paying rent for an apartment I only lived in for 10 weeks, so I tried spending the year living out of my suitcase and staying with friends in my off-weeks.
"It was exhausting - you just never recharge, so I feel like that's impossible."
Daniell is currently based in New York with his partner, but they plan to relocate to London in March.
Generally, tournament organisers also cater for their players at events, but Daniell forked out $15,000 for additional dining last year.
"It's another big cost that I don't often think about. If you were living at home and doing your own cooking, your expenses would be tiny by comparison."
Professional athletes can't crib on their nutrition - low-cost options like McDonalds or Pizza Hut aren't staples of their diet.
"Almost every night, you have to eat in a restaurant and you can't have small portions. Often I need two mains… 'Os' needs seven."
Thankfully, Daniell isn't known for his racket-smashing tantrums, but maintaining his weapon of choice also takes a toll on the wallet.
"I'm probably at the lower price range for restringing, but it still cost me just under $5000 last year."
Physio and massage are another 'nice to have' on tour, but essential for players to keep their bodies in good nick.
"If you were going to take optimal care of your body, you'd spend a couple of hours a day on massage and treatment.
"That's a luxury available only through a wealthy and generous federation, or success and it's a chicken-and-egg situation. You can't afford these things without success, but you can't get success without all these little things."
Luckily, the ATP provides basic medical resources at tournaments and those practitioners deliver yeoman service.
"They're very, very good at what they do," says Daniell. "They work bloody hard - they'll be here from 9.30 to 1am at times.
"It's a big shift for them and I think everyone gives them the respect they deserve."
Still, additional treatment and supplements cost Daniell another $7000 last year.
INJURY & ILLNESS
If players don't stay on top of their health issues, any prolonged absence from the tour can cost them earnings.
The year after Daniell won the Auckland doubles title, he suffered a herniated disc in his back that kept him sidelined for eight months.
"I tried to come back early to play at the Commonwealth Games, which had tennis for the first time, and re-injured it."
Daniell's ATP profile shows his earnings that year were just $2000.
Sometimes, the Kiwi has questioned his existence on the world tennis stage, especially during those unfruitful early years, battling on the tour's third-tier Futures circuit.
"Everyone has those doubts," he considers. "Maybe not everyone.
"If you're a guy like Alex Zverev or Tsitsipas, who get very good very young and are top of the world in juniors, and get picked up by management companies and have millions of dollars in the bank before they turn 16... that's a different story.
"But that's about one player in 10 million."
Amid a horror string of singles results - 10 straight first-round losses - Daniel remembers a particularly dispiriting thrashing by a college player in Toulon.
"I hadn't cried since I was 13, but I remember going out to the carpark, putting a towel over my head and I absolutely lost it.
"I just thought, 'What am I doing here? This is the opposite of enjoyable'.
"I gave myself one more tour and then I was done. Luckily, I went to Israel for three weeks and had my best results ever - semis, quarters and finals in singles, and won maybe two doubles titles.
"That brought me back from the very brink."
Another time, Daniell was winning matches in China, but wasn't enjoying the process.
"There was an earthquake near where I was that killed a few hundred people… I was about 22 or 23. If you don't enjoy playing at those lower levels, there's just nothing that affirms you as a tennis player.
"People aren't watching, you're not earning money - you're losing a helluva lot of money - and it's only the dream that keeps you going."
After Daniell returned to his London base, Sammell laid down the law, accusing him of being "a tourist" and "worshipping at the chapel of bullshit".
"That was really the turning point in my career," he chuckles. "I started training more intensely mentally, getting better results and really moving forward in doubles."
You also have to wonder what a bright young man like Daniell could be doing with his talents, if he wasn't bouncing between airports, hotels and tournament venues. Chalk that up as an opportunity cost.
"Any career, any decision has that 'what if' factor, but tennis is a very short, intense part of my life and I'm not dreading the post-tennis career."
Daniell hopes to play at least five more years and has a fair idea what career he wants to pursue, once he's finished chasing balls around a court, even if he hasn't quite hashed out the details yet.
"The big plan is I want to move back to New Zealand," he says, "I feel deep ties to this place… and I want family.
"I want to do something, either in the start-up world or non-profit that makes the environment better. I pointedly haven't thought about any detail, because I feel like the landscape will have changed before then.
"There's no point coming up with the big idea now, but I'm very passionate about that side of things."