World Baseball Classic Begins as Polymarket Emerges as Tournament Gauge
The World Baseball Classic, or WBC, is an international tournament sanctioned by the World Baseball Softball Confederation and led by Major League Baseball. As the 2026 tournament got underway at Tokyo Dome, decentralized prediction market Polymarket emerged as a new gauge of the competition. It allows crypto users to put money behind game outcomes, providing a real-time snapshot of the market’s collective view.
During the Tokyo leg of the 2026 WBC, Polymarket opened a market on Taiwan’s first game against Australia. The market at one point put Taiwan’s chances of winning at nearly 70%, with the probability continuing to fluctuate as wagers and pregame information came in. Reports also noted that early trading had favored Australia, underscoring that prediction-market probabilities are not definitive and adjust in real time to lineups, injuries and trading activity.
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2 original reportsThe Backstory
The history behind this eventPolymarket Prematurely Settles WBC US Advancement Bet, Exposing UMA Oracle Flaw
Polymarket is a decentralized prediction market powered by smart contracts that uses UMA’s “optimistic oracle” to submit event outcomes. A determination automatically takes effect if no one disputes it during the challenge period. The WBC incident shows that, without real-time verification or a challenger, incorrect information can enter the settlement process and directly affect participants’ interests and market credibility.
After the United States suffered a surprise loss to Italy in the World Baseball Classic, its advancement still depended on group standings and runs-allowed calculations. Polymarket, however, had already determined by late February 2026 that the US team would advance and settled the market accordingly. Because no one raised an objection during UMA’s challenge period, the smart contract automatically executed the erroneous result. Reports did not disclose the market’s trading volume or the amount affected.
Polymarket Opens on Korea-Australia WBC Game as Data Highlights Chinese Taipei’s Path to Advance
The World Baseball Classic group-stage game between South Korea and Australia will affect not only the two teams’ records but also whether Chinese Taipei can advance to the quarterfinals in Miami. On-chain prediction market Polymarket allows traders to wager on the result, translating market consensus into real-time probabilities and demonstrating the analytical value of Web3 tools for major sporting events.
After the market opened, Polymarket put South Korea’s win probability at 73%, showing a clear market preference for a Korean victory. The analysis outlined two scenarios for Chinese Taipei to advance: South Korea must defeat Australia, and Chinese Taipei must also meet a specific runs-allowed ratio threshold used to determine the group standings. The available information did not disclose the market’s opening date, trading volume or the threshold figure.
Polymarket Gives Chinese Taipei Slim Odds Against Japan as WBC Hopes Fade
The World Baseball Classic matchup between Chinese Taipei and Japan will be pivotal to Chinese Taipei’s chances of advancing from the group stage, with Japan holding the edge in both overall strength and market confidence. Decentralized prediction market Polymarket allows traders to wager on outcomes, with contract prices translating into real-time probabilities. The platform accurately predicted the result of Chinese Taipei’s opening game, drawing attention from Taiwanese fans to its on-chain crowd forecasts.
The game was scheduled to begin at 6 p.m. that evening. Polymarket’s pregame data put Japan’s win probability at 90.8%, compared with just 9.6% for Chinese Taipei, reflecting a nearly one-sided market. As the group stage enters a critical phase, Chinese Taipei now has only two possible paths to advance. It must push for a win over Japan while also monitoring other results in the group before it can know whether it has secured a place in the next round.
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