#4 Zack Greinke (2015)
Zack Greinke was absolutely dazzling in 2015, and he would soon be rewarded that offseason by the Arizona Diamondbacks with an annual salary of upwards of $30 million.
Overall his season was magnificent, but his first half stats were absolutely incredible. He entered the All-Star break with only eight wins in 18 starts, but that was no real indication of how well he was pitching.
In 123.1 innings pitched, Greinke sported a 1.39 ERA with 106 strikeouts to only 20 walks. He faced 466 batters, only allowing 84 hits. While his strikeout per 9 innings ratio wasn’t spectacular at 7.7, this really wasn’t his game at this point in his career.
What really stood out to me was his ERA at only 1.39. To maintain an ERA that low over 123.1 is something that is very rare to see.