18 pitches, $400,000 and inside information: why microbetting is so easy to manipulate

A baseball game contains hundreds of pitches. Federal prosecutors are preparing to focus on just 18 of them.

In a September court filing, prosecutors identified approximately 18 pitches thrown by Cleveland Guardians closer Emmanuel Clase across 17 games between May 2023 and May 2025. They say bettors received advance information about those pitches and used it to wager on outcomes such as pitch velocity or whether a pitch would be called a ball. One of the pitches came during the 2024 MLB playoffs. Covers, reporting on the court filing.

Clase and fellow Guardians pitcher Luis Ortiz have pleaded not guilty. Jury selection in their federal trial is scheduled for November 2026. The claims discussed below are allegations, not facts established by a verdict. US Department of Justice, Associated Press.

Whatever the eventual verdict, the case exposes a structural problem in one of sports betting’s fastest-growing products: microbetting.

When a sportsbook lets customers bet on a single pitch, possession, serve or next play, the settlement event may be heavily influenced by one participant while having almost no effect on the final result of the game. That creates a very different integrity problem from a traditional match bet.

What prosecutors say happened

According to the federal indictment, Clase allegedly began coordinating specific pitches with bettors in May 2023.

The markets were remarkably narrow. Bettors could wager on questions such as:

• Will the pitch be a ball or hit-by-pitch?
• Will its velocity be above or below a specified number?
• What type of pitch will be thrown?

Prosecutors allege that Clase sometimes agreed to throw a slower slider instead of his much faster cutter, or to place a pitch low and outside the strike zone. They say bettors placed more than 100 pitch-speed and Ball/HBP straight bets and parlays using advance information.

Some individual examples were substantial. On 3 June 2023, prosecutors say bettors won approximately $38,000 after betting that a Clase pitch would be a Ball/HBP and/or slower than 94.95 mph. The pitch was an 89.4 mph slider that bounced before reaching home plate. Four days later, bettors allegedly won around $58,000 on another pitch expected to be a ball and/or slower than 94.95 mph.

On 12 April 2025, prosecutors allege bettors won about $15,000 on a pitch expected to be a Ball/HBP or below 98.45 mph. The indictment includes an image of the pitch hitting the ground well before the plate.

The government says bettors ultimately won at least $400,000 on pitches thrown by Clase. Federal indictment.

The most revealing number may be 17 out of 18

The prosecution’s September list contains 18 Clase pitches. Seventeen were the first pitch of an at-bat; only one was listed as pitch number two.

That pattern illustrates why microbetting creates an unusual integrity risk.

A bettor does not need to know who will win the game. They do not need to know whether Cleveland will score, or even how the at-bat will end. They only need advance information about one event lasting a fraction of a second.

In a pitch-level market, one participant may have enormous influence over that event.

Even a playoff game appears on the list

The government’s list includes the first pitch Clase threw to Detroit’s Matt Vierling in Game 1 of the 2024 American League Division Series on 5 October. It was a roughly 93 mph slider outside the strike zone.

Nothing dramatic happened to the game. Clase recovered, retired the side and Cleveland won 7-0. Yet prosecutors say that pitch will form part of their betting case.

This is what makes alleged microbet manipulation fundamentally different from fixing a match.

A player trying to deliberately lose a baseball game would need to overcome teammates, opponents and dozens of unpredictable events. A player trying to influence one pitch may only need to throw one slider into the dirt. The game can continue normally afterwards.

Controllable does not mean guaranteed

Another episode in the indictment shows the limits of that control.

Prosecutors say bettors placed parlays involving eight specified Clase pitches being Ball/HBP. Seven of the eight pitch legs succeeded. The eighth failed for a revealing reason.

On 28 May 2025, Clase allegedly threw the selected pitch outside the strike zone as expected, but Dodgers hitter Andy Pages swung at it. The official result was therefore a strike, and the wagers lost.

A pitcher has enormous influence over pitch location, velocity and selection. He cannot completely control the batter, the umpire or every other variable used to settle the market.

Microbetting is therefore not guaranteed to be manipulated successfully. It is simply far more controllable by an individual participant than the result of an entire game.

How unusual betting on Ortiz triggered an alert

For sportsbooks, the most important part of the story may involve Luis Ortiz rather than Clase.

Unusual betting activity was identified around two extremely specific Ortiz markets in June 2025:

• the first pitch of the second inning against Seattle on 15 June;
• the first pitch of the third inning against St. Louis on 27 June.

In both cases, the betting interest focused on the selected pitch being a ball or hit-by-pitch. A betting-integrity firm flagged the activity and forwarded it to MLB. The league placed Ortiz on non-disciplinary leave and began an investigation. Associated Press.

The indictment later added more detail. For the 15 June pitch, bettors allegedly wagered approximately $13,000, with a payout of roughly $26,000 after Ortiz threw a ball. Prosecutors say Ortiz was to receive approximately $5,000 and Clase another $5,000 for arranging it.

For 27 June, bettors allegedly wagered around $18,000 that the selected pitch would be a ball. It was, producing a payout of about $37,000. Prosecutors allege that Ortiz and Clase were each to receive approximately $7,000.

This time, the betting pattern was unusual enough to trigger the monitoring system.

What does abnormal betting look like?

Integrity monitoring is not simply a search for customers who win too much. It looks for activity that does not fit the normal profile of a market.

Potential signals include:

• a sudden increase in betting volume;
• an abnormal movement in price or available liquidity;
• many wagers concentrated on one narrow outcome;
• linked activity across accounts, locations or operators;
• betting patterns that coincide with a specific sporting event or piece of information.

Consider a normal MLB moneyline. It may already contain thousands of bets and substantial volume. Another few thousand dollars can disappear into the normal flow.

Now consider a market on the first pitch of the third inning being a Ball/HBP. It naturally attracts much less money. A sudden concentration of large wagers on precisely that outcome is therefore more conspicuous.

This creates a paradox. A micro market may be easier for one participant to influence, but it can also be easier to flag once the betting activity becomes sufficiently abnormal.

Why did detection take so long?

That is the uncomfortable question raised by the case.

Prosecutors allege that activity involving Clase began in May 2023 and continued into 2025. Earlier filings referred to suspicious activity across a much wider group of games before prosecutors narrowed the pitches they intend to present at trial.

The indictment also alleges that bettors spread wagers across multiple accounts and platforms and sometimes used parlays.

An operator examining only its own sportsbook may therefore see only one fragment of the total activity. A bet that looks notable but inconclusive in isolation can become much clearer when combined with data from other operators, a league and an integrity-monitoring company.

That is why cross-operator information sharing matters. The risk does not stay inside one sportsbook merely because each platform can see only its own customers.

Parlays increased the potential payout

Prosecutors say bettors used microbet outcomes as legs in parlays to generate larger payouts. Approximately 16 parlays allegedly contained bets on eight specified Clase pitches.

This matters because a simple stake limit becomes less effective if an event influenced by inside information can be inserted into a higher-paying combination.

The response from MLB therefore targeted both problems.

MLB introduced a $200 limit

On 10 November 2025, MLB announced safeguards agreed with its authorised sportsbook partners. Pitch-level bets would be:

• capped at $200 per wager;
• prohibited from being included in parlays.

According to MLB, operators representing more than 98% of the US sports betting market were implementing the restrictions. Associated Press via PBS News.

The league’s explanation went directly to the structure of the market. Most player propositions depend on a sequence of events involving multiple participants. A pitch-level microbet can instead be determined by one player and may be almost irrelevant to the final result of the game.

The $200 cap reduces the economic value of obtaining or purchasing inside information. Removing these markets from parlays prevents bettors from multiplying that value through combinations.

Neither measure makes attempted manipulation impossible. Together, they make it much harder to scale.

Why microbetting limits should be smaller

Sportsbook limits usually reflect expected financial exposure, market liquidity and confidence in the price. Micro markets add another important variable: how many people can materially control the settlement event?

Think of the spectrum:

• A baseball moneyline depends on hundreds of pitches, dozens of players, managerial decisions, fielding, hitting and randomness.
• A season championship market depends on months of competition.
• A next-pitch velocity market may depend primarily on one pitcher moving his arm once.

As the event becomes narrower, there is less diversification in the underlying sporting outcome. One participant’s influence becomes proportionally larger.

From an integrity perspective, that justifies dramatically lower limits even when a sportsbook believes it can calculate a reliable price.

The larger lesson

Microbetting is attractive because it turns every few seconds of a game into another market. That creates engagement, volume and thousands of new outcomes to price.

The same property creates the vulnerability.

When the question shrinks from Who wins tonight? to Will the next pitch be a ball?, the number of people capable of materially influencing the result can shrink from dozens to one.

The Clase and Ortiz case is therefore more than a story about two pitchers and a group of bettors. It is a case study in market design.

The more granular sports betting becomes, the more important conservative limits, surveillance, cross-operator data sharing and restrictions on parlays become. Sometimes the right question for a sportsbook is not simply whether it can price a market.

It is whether that market should be large enough for anyone to make serious money from controlling it.