Better monitoring helps catch people making fraudulent bets on sports

Cleveland Guardians pitcher Emmanuel Clase reacts after the Guardians defeated the Baltimore Orioles in Cleveland, Tuesday, July 22, 2025. Photo by: Sue Ogrocki / AP

Editor’s note: “Behind the News” is the product of Sun staff assisted by the Sun’s AI lab, which includes a variety of tools such as Anthropic’s Claude, Perplexity AI, Google Gemini and ChatGPT.

Professional sports leagues have grappled with several high-profile cases of athletes violating betting policies, with Major League Baseball facing particularly notable violations.

The Cleveland Guardians organization has been at the center of recent investigations, with two pitchers currently placed on nondisciplinary paid leave as part of MLB’s sports betting probe.

Three-time All-Star closer Emmanuel Clase became the second Guardians pitcher to face scrutiny, joining Luis Ortiz, who remains on leave through Aug 31. These cases highlight the ongoing challenges leagues face in maintaining the integrity of their sports while navigating the expanding landscape of legalized sports betting.

The Guardians players are the latest to face potential consequences.

In June 2024, Tucupita Marcano was banned for life after placing 387 bets totaling over $150,000, including wagers on his own team at the time, the Pittsburgh Pirates, even while he was injured. Marcano is the first active player in a century to receive a lifetime MLB ban for gambling [1][2].

Michael Kelly served a one-year suspension for betting $99.22 on nine MLB games as a minor leaguer, none involving his team, before being reinstated in June. He netted a modest $28 from those bets [3][4].

The crackdown on gambling isn’t unique to baseball — high-profile cases have emerged across the NFL, NBA and NCAA:

NFL cases

• Calvin Ridley was suspended for the entire 2022 season for betting on his own team while away from football [11][12].
• Jameson Williams and Stanley Berryhill each received six-game suspensions for betting at team facilities [11][12].
• Quintez Cephus and C.J. Moore were suspended indefinitely for NFL wagers [11][12].
• Isaiah Rodgers and Rashod Berry were suspended indefinitely and released after betting on NFL games, including bets on their own team [11][12][13].

NBA cases

• Jontay Porter was banned for life in 2024 for betting on NBA games using someone else’s account and sharing confidential information to fix statistical prop bets in his own games, which resulted in over $1 million in winnings for the group involved [14][15][16].
• Malik Beasley is under federal investigation for placing NBA and prop bets during the 2023-24 season [17].
• Terry Rozier is under investigation for suspicious betting activity involving prop bets when he was with the Charlotte Hornets [18].

NCAA/college sports

Multiple college programs have faced violations. At Fresno State, basketball players Mykell Robinson and Jalen Weaver allegedly made bets on their own stats and team performance through daily fantasy sports [19]. Texas Longhorns football had two players who placed bets via PrizePicks during the 2024 season, with one athlete becoming permanently ineligible [20]. Iowa and Iowa State saw multiple athletes across various sports face penalties after an investigation uncovered illegal bets, including on their own teams [21][22].

How athletes get caught

Athletes are most commonly detected through rigorous integrity and monitoring systems:

• Irregular betting activity: Betting integrity firms monitor patterns and flag suspicious betting actions — such as abnormal wagers on very specific in-game events or spikes in betting volume correlated to athlete performance [23].
• Location data: Legal sportsbooks use geolocation technology. If a player places a bet from a team facility (where betting is strictly prohibited), it is quickly flagged and reported [24].
• Manual reporting: Sometimes, coaches or staff notice suspicious behavior and proactively notify league officials [19].
• Data sharing: Modern sportsbooks are required to cooperate with leagues, making it harder for athletes to hide their actions [23].

Leagues’ education efforts

Most leagues conduct comprehensive education programs:

• Rule briefings: At the start of each season, athletes attend mandatory training on gambling rules, including examples of violations and real-life disciplinary outcomes.
• Ongoing reminders: Teams and leagues provide continuous reminders, posters in locker rooms and access to ethics hotlines.
• Reporting mechanisms: Leagues have established clear policies on how players can report suspicious approaches or betting attempts [25].

The NCAA has been urged to modernize and intensify its programs due to the increasing ease and prevalence of legal sports betting [25].

Should gamblers worry about fixed outcomes?

• Suspicious matches detected: In 2023, 1,329 suspicious matches were detected over 11 sports across the globe by Sportradar Integrity Services, 667 of which occurred in Europe. Asia (302) and South America (217) were the other leading continents. That accounts for 0.21%, or 1 in 467 events, monitored by that system [37].
• Detection systems: The very fact that athletes are being caught demonstrates that monitoring systems — spotting abnormal betting patterns and investigating thoroughly — work in real time [23][24].
• League oversight: Leagues and independent monitors watch for spikes and anomalies to quickly investigate potential match-fixing.
• Transparency: Professional sports’ embrace of legal, regulated markets has made monitoring more effective compared with unregulated or gray markets [26][27][28].

While cases of match-fixing do occur, they are rare at the highest levels due to the likelihood of detection, severe penalties, and the relative financial security of most major-league athletes.

Why Las Vegas and US integrity monitoring is so effective

Henderson-based U.S. Integrity, founded in 2018, is a sports integrity monitoring company that works with sportsbooks across North America to prevent sports-betting fraud by monitoring for abnormal activity, including detecting misuse of insider information, such as a player betting on their own sport[41]. The U.S. Integrity monitoring system is highly effective due to several key factors:

• Advanced analytics and real-time data: U.S. Integrity uses robust analytic tools to monitor betting behavior, instantly analyzing millions of wagers across regulated sportsbooks. These analytics benchmark every bet against normal activity, looking for statistical anomalies or suspicious patterns in real time [29][30][31].
• Data integration and location tools: Las Vegas-based monitors benefit from direct access to vast, granular wagering data provided by the city’s concentrated, regulated sportsbook industry. They leverage powerful integration with geolocation and customer identity systems [30][31].
• Regulatory culture and history: Las Vegas has decades of experience policing betting markets, leading globally in regulatory standards and industry best practices. Strict state requirements mean that sportsbooks must report suspicious activity [30][31].
• Human intelligence: The system isn’t purely algorithmic. Las Vegas firms supplement data-crunching with hands-on investigative teams, close relationships with leagues and universities, and direct reporting hotlines [29][32].
• Proactive prevention: U.S. Integrity deploys technologies that aim to prevent illicit betting before it occurs, including encrypted data transfer to verify who is allowed to bet and the “ProhiBet” system [33][34][35].

Notorious cases

Two particularly infamous figures shaped modern gambling policies:

• Art Schlichter, an NFL quarterback, was drafted by the Baltimore Colts in 1982. His career rapidly unraveled due to a severe gambling addiction. Schlichter bet on NFL and college football games, was suspended indefinitely by the NFL in 1983, and eventually spent time in prison for related crimes [36].
• Tim Donaghy served as an NBA referee from 1994 to 2007 before resigning amid a massive FBI investigation. He admitted to betting on games he officiated — using inside information on player injuries, referee assignments and team conditions. Donaghy pleaded guilty to federal charges including conspiracy to commit wire fraud and received a 15-month prison sentence[39][40].

Both cases demonstrated the grave consequences of insiders wagering on their sports and continue to inform modern education efforts and detection measures.