CLEVELAND -- There was a point in the second half last season when former Indians pitching coach Mickey Callaway sat down with Josh Tomlin to go over the starter's pitch usage. It was more of a reminder than anything else. Callaway wanted to again stress that Tomlin needed to lean hard on his curveball, and the coach pulled up numbers to back that up.
"I used to always say my cutter is my best pitch," Tomlin said. "But, looking at the data, looking at the stuff that doesn't lie, then you see it. OK, there it is. Curveball."
Callaway was named the Mets' new manager earlier this week, but his fingerprints will likely remain on this aspect of the Indians' pitching staff. During his five-year tenure as the Tribe's pitching coach, Callaway brought a simple concept to the forefront of his pitchers' minds: Throw their best pitch as often as possible. For Cleveland's current crop of arms, the curve quickly became an overwhelming weapon.

During the 2017 campaign -- one in which the Indians led the Majors in ERA, Fielding Independent Pitching and set single-season MLB records in strikeouts (1,614) and strikeouts per nine innings (10.1) -- the Tribe's staff also paced baseball in curveball percentage (17.6 percent, per Statcast™). Cleveland's 15.6-percent rate of throwing curves over the '16 and '17 seasons also ranks first in the Majors during that time.
It helps to have the likes of Corey Kluber, Trevor Bauer, Carlos Carrasco, Cody Allen and Tomlin on the pitching staff, but Callaway convinced them to continually increase the percentage of curves thrown. The turning point can be traced back to July 2015, when the Indians' monthly curve rate (11.9 percent) overtook the MLB average for the month (9.9). Cleveland stayed ahead of the mean in every month through the end of the '17 season.
In the past two postseasons combined, Cleveland pitchers featured the curve 22 percent of the time.

"The curveball is harder to throw in the zone for strikes," Callaway said in June, when his pitchers threw curves 18.7 percent of the time for the month. "I think what we were missing is that, when you throw breaking balls, you get the benefit of more chase out of the zone. So your strike percentage is actually higher, even though your zone percentage might be lower."
Over the past two seasons combined, Cleveland has held batters to a .176 average, .272 slugging percentage and .206 weighted on-base average on curveballs, according to Statcast™. Each of those marks ranked first in the Majors, which had averages of .215 (batting), .346 (slugging) and .249 (wOBA) in those categories.
During that same two-year period, Cleveland led the American League in ERA (3.58), FIP (3.62), strikeouts per nine innings (9.4), strikeouts (3,012) and strikeout-to-walk ratio (3.5), among other areas.
"You have less hard contact. You have less balls in play for average. You have less hits with that pitch," Tomlin said. "So, let's throw that more. OK, and next thing you know, you go through a stretch where you get six, seven innings per outing and you get your ERA down a little bit lower and you give your team a chance to win."

No matter who the Indians hire as their new pitching coach -- the search is underway for Callaway's replacement -- they will inherit mostly the same pitching staff.
The starting rotation trio of Kluber, Carrasco and Bauer is slated to return, along with Danny Salazar and Mike Clevinger. Tomlin has a $3 million team option that looks like a no-brainer for Cleveland to pick up. Relievers Bryan Shaw and Joe Smith will be eligible for free agency, but the bulk of the Tribe bullpen will remain intact.
The curveball will also return as a primary weapon for the Indians' overpowering staff.
"It's just happened over time," Callaway said in June. "I think there's more information on arm care, health, things like that, that are leaning more toward velo than breaking balls, when it comes to problems with the elbow and things like that. So, that probably relieves some tension in pitching coaches' minds and players' minds that they can go out there and throw 50-percent breaking balls and they're going to be OK."