Opposing lawsuits revealing the split between former three-belt welterweight champion Errol Spence Jr. and his only trainer as a professional, Derrick James, have highlighted the frequency of verbal contracts in the sport.

In a discussion between former world titleholders Paulie Malignaggi and Chris Algieri on Friday’s episode of ProBox TV’s “Deep Waters,” the focus to construct iron-clad agreements between fighter and trainer before a bout seems essential now that such a strong union has unraveled over such uncertainty.

While the 34-year-old Spence (28-1, 22 KOs) has claimed in his lawsuit against James that the fighter believed he had met and exceeded the requirements of their long-standing oral contract by paying James $350,000 following Spence’s July TKO loss to Terence Crawford, James’ lawsuit claims he is owed at least $2.15 million more from that bout and “no less than $5 million” for Spence’s other pay-per-view bouts.

Dating to their first pro bout, when Spence was paid $2,500 and James’ verbal agreement to a 10 percent cut netted him $250, that percentage figure became the root of the dispute, as Spence elevated from 2012 U.S. Olympian to world champion and his career ascent led him to lucrative pay-per-view bouts against Mikey Garcia, Shawn Porter, Danny Garcia, Yordenis Ugas and then Crawford – for the undisputed welterweight strap.

While Spence claimed in his lawsuit that he based his trainer fees on his bout-agreement purse (which was $2.5 million for Crawford), James claims in his lawsuit that he is entitled to what Spence gained from the pay-per-view upside of total buys.

“You have to have an agreement with the trainer beforehand,” Malignaggi said. “I can remember hearing about Oscar De La Hoya would have a set agreement [for a flat fee] when he was hiring trainers, like $200,000 for each camp. He wasn’t going to give 10 percent of [such a large] amount of [pay-per-view] money. That was astronomical.”

In James’ lawsuit, his attorney claims Spence was advised by “someone named Al” that paying James $350,000 for the Crawford bout was generous. It was not revealed in the lawsuit whether that individual was Spence’s manager and Premier Boxing Champions founder Al Haymon.

But Spence, in James’ lawsuit, apparently texted James in mid-February to tell his trainer he wanted to make right on their dispute and intended to send him an extra $2.15 million – but needed to wait until the funds became “liquid.”

The money never came.

Malignaggi said the split should have been hashed out before the Crawford fight, and said because of the amount of money, it should be “a little more than verbal.”

“In this particular case, it’s obviously a breakdown in communication,” Algieri said. “A lot of people say, ‘The trainer gets 10 percent.’ Well, that’s not really the way it goes. There’s nothing written in stone that that’s how it goes. That’s why we have contracts. When you’ve got a guy making $25 million [as Spence did from pay-per-view proceeds], that’s a lot from the guy who went out there to fight. So there has to be communication.”

Algieri thought it regrettable that the difference can end a highly successful pairing between the driven trainer and gifted fighter, who accomplished so much together in Texas.

“Money does a lot of damage. It can damage families,” Algieri said. “The trainer-fighter relationship … it’s very close to blood. It becomes very familiar. You care about each other, but money makes things funny, as the song goes.”

Algieri said he can see both sides of the argument. James feels dug in that he is owed 10 percent of earnings, but Spence can think “Our non-verbal agreement is that you were going to get me to win. I didn’t win. So this is what you’re getting now.’”

Algieri believes handshake deals and crystal-clear communication can still work in these transactions.

“You’ve got to have these lines set [fighter to trainer]: ‘Listen, man, this is where we’re going to be …’” Algieri said. “We’re in April now, and the fight was in July.”

Malignaggi suggests a contract is the best way for pay-per-view fighters to proceed.

“It needs to be one fight at a time,” he said. “When you’re talking about the fighter-trainer relationship, things can change fast.”