You don't need to be watching the pitch to know when a goal's been scored. You just need to keep an eye on Choi Kyung-Sik.
The co-commentator for South Korea’s KBS TV is at the Suwon World Cup Stadium, about an hour south of Seoul, for Suwon Samsung Bluewings' home match against Daejeon Citizens.
It's a one-sided affair – the K-League's fourth-from-bottom side, the Bluewings, strolling to a four-nil win against their third-from-bottom opponents.
But when the goals go in, Choi is full of animated excitement, refocusing quickly on his monitor to analyse each replay.
Sure, some of it is TV technique. But there's no mistaking the genuine enjoyment he gets from watching a well-worked goal. No mistaking either, the undercurrent of regret he feels about what's happened to his cherished game.
Since May when the scandal broke," he says, "I've seen fewer spectators at the grounds. And when a match is underway, if a forward makes a mistake or a defender misses the ball, I can feel the suspicion from the crowd. I even hear children in the stands asking their parents: Why did the player do that?"
The two teams he's watching tonight have both lost squad members to the biggest scandal ever to hit the 28-year-old professional league.
In all, 46 players have been indicted for match fixing 10 have received life bans two former players have killed themselves.
Much has been made – and rightly so – of the footballers' short careers and low wages (a minimum of just $11,000 a year, though the big names earn many times that), the loyalty to former teammates who have drifted into the shady world of illegal betting, and the hierarchical nature of football here, where junior players do what their elders tell them, even if it's against the rules.
But Choi says the problem starts long before they reach the professional ranks.
As well as a commentator, he's head of physical education at a school on Seoul's outskirts, with a record of footballing success.
He says until recently the only way for young players to get into a potentially career-making university side was to play for a team that finished in the top four of the national schools competition.
That kind of pressure, he says, led to corruption at school level: "The students would get used to that atmosphere. They felt and even knew what was going on behind the scenes. And that mindset persisted into the professional game."
He says it's cemented at two further stages along the way. First in the University League:
I saw a U League player once – he wasn't well off at all – and suddenly he had a fancy foreign car and was spending a lot of money. And there was a rumour around him that he was involved in corruption."
Then, he says, more problems arise when players do their compulsory two years' military service. The best footballers play for the military side, Sangmu, which competes in the 16-team K-League.
When they play for Sangmu they're on less than a hundred dollars a month and they're easily lured into wrongdoing… And then when they join professional sides again, they spread that practice."
Nine of the indicted players in the scandal played for Sangmu. The team has been threatened with exclusion from next year's competition.
Indeed, the K-League has announced a raft of measures: pensions for players, a doubled minimum wage, promotion and relegation to give teams more to play for, even mandatory lie detector tests.
But Choi Kyung-Sik says it would be a mistake to focus only on the elite level: "This incident calls for a tremendous new wave of rebuilding throughout the entire game, from elementary school, to middle school, to college, to the professional teams.
"Schoolboy and professional players alike need the right education so that this kind of scandal can never happen again. We should do our utmost for that".