Zack Greinke Made A Change, And The Dodgers Keep Winning

The Dodgers have been on an absolute tear for more than two months. And Clayton Kershaw, who possesses an impossible 1.72 ERA as the calendar nears September, looks all but certain to win the National League Cy Young Award for the second time in three years. But we really need to talk about Zack Greinke and how well he's pitched since he began throwing his changeup more frequently in recent weeks.

After missing a month with a broken collarbone early in the season, Greinke struggled in three of his next four starts. But since then, he's been showing the sort of dominant form he's only displayed in flashes since his brilliant 2009 season in Kansas City. Last night, Greinke pitched 8.2 innings and struck out nine. (This does count, even though he did it against the Cubs.) It was also his fifth victory in as many starts this month. All told, Greinke has made 13 starts since the Dodgers began what is now a 47-12 streak a little more than two months ago. He's 10-1, and the Dodgers also won the two games in which he didn't factor into the decision.

L.A.'s current streak began on June 22, when Greinke got the start a couple of hours down I-5 in San Diego—his first start there since he plunked Carlos Quentin with a pitch back in April, triggering the brawl that resulted in Greinke's collarbone injury. Heading into that game against the Padres, Greinke had an ERA of 4.22 ERA and a SO/BB ratio of 2.33. Hard though it may be to believe now, the Dodgers were 30-42 and in last place in the National League West at the time, 9.5 games out of first.

Greinke has pitched past the sixth inning in all but four of his starts since then. He's allowed more than three earned runs just three times. His ERA has fallen all the way to 2.86. He has 77 strikeouts and just 24 walks in his last 13 starts—totals that include a seven-walk outing against the Rockies in early July, when L.A.'s offense bailed him out. Greinke is also inducing a lot more ground balls: 71 in his first nine starts, 133 in his last 13.

This chart illustrates what's different. Notice the spike in the percentage of changeups Greinke has thrown in the last month:

In June, Greinke threw his changeup just 9.58 percent of the time. In July, that number ticked up slightly, to 10.50 percent. But in his five starts this month, fully one in five of his pitches (20.99 percent) has been a changeup. He's throwing it twice as frequently as he did last month; he hasn't used it this often in a full month at any point in his career.

In fact, per Brooks Baseball, Greinke has already thrown nearly as many changeups in five starts this month (115) as he did in 12 combined starts in June and July (125). He's also gotten hitters to swing at 55.65 percent of his changeups in August.

The chart below demonstrates how Greinke has thrown more changeups of late at the expense of his three power pitches: the four-seam fastball, sinker, and cutter. Hitters just haven't been able to catch up. All of a sudden, the $147 million contract the Dodgers signed Greinke to last winter looks like a perfectly reasonable investment.

Photo credit: Associated Press