MLB's investigation found that Marcano didn't just bet on baseball frequently -- he's claimed to have gambled more than $150,000 across nearly 400 baseball bets, including on MLB and international contests -- but that he even bet on his own team, then the Pirates. "[Almost] all of Marcano's Pirates bets were on which club (the Pirates or their opponent) would win the game or whether there would be more or less than a certain number of runs scored in the game," MLB said in a press release.
It's notable that Marcano did not appear in any of the games that he bet on because of his injury. He also denied having inside information that influenced his bets. MLB estimates that he won just 4.3% of his MLB-related gambles.