There has been a recent rise in cryptocurrency based betting services to meet the demand of a market that prefers its use over fiat currency. While popular, these escrow services follow an unfavorable trend of utilizing cryptocurrency in a centralized manner, creating counterparty risk that did not previously exist. This occurs as users entrust the ownership of their cryptocurrency to services which are susceptible to hacks and leave little recourse to victims of theft. We propose a sports betting exchange which solves this issue by means of decentralization, removing central points of failure to allow the use of cryptocurrency without counterparty risk. A sports betting exchange is a marketplace for the trade of sporting outcomes. Unlike a traditional sports betting platform, a sports betting exchange eliminates the need for a central bookkeeper and instead enables users to place bets against one another. This paper details Block Sports, a decentralized sports betting exchange that approaches the concept of a blockchain-native sports betting platform with two key objectives — creating a decentralized and trusted framework for sports betting and providing a rich user experience through an off-chain service layer. Utilizing the Neo blockchain, a solution is proposed which integrates a decentralized oracle consensus network with a series of smart contracts, allowing users to place bets on sporting outcomes with NeoGas (GAS). The result is a platform that solves the issue of counterparty risk while still remaining competitive with traditional sports betting exchanges.