Hunter Greene is MLB's hardest-throwing starter; here's how Reds rookie can take next steps to become an ace | CBS Sports Headlines Hunter Greene is MLB's hardest-throwing starter; here's how Reds rookie can take next steps to become an ace Greene’s fastball has averaged 100 mph in his first two … Continue reading Hunter Greene is MLB's hardest-throwing starter; here's how Reds rookie can take next steps to become an ace