Heavily dependent on one pitch to be effective, Charlie Morton has his sinker dipping and diving just the way he wants right now.
Morton's return to Pittsburgh's rotation couldn't be going much better, and he'll look for a fifth win in as many starts while trying to help his Pirates teammates make it six in a row Tuesday night against the visiting Chicago White Sox.
It might not seem like Pittsburgh (36-27) was missing much as Morton recovered from offseason hip surgery through late May, but having the right-hander healthy for the first time in a while has made a considerable difference.
Just 32-53 with a 4.31 ERA over his first 119 starts as a Pirate, Morton is 4-0 with a 2.05 ERA over four in 2015. He struck out six over 19 innings in his first three, but fanned that many while allowing only three hits in 7 1-3 innings in Wednesday's 2-0 win over Milwaukee.
Morton has allowed just eight fly balls in this stretch, and with his signature sinker especially effective, his 70.0 ground-ball percentage is the best in the majors among those who have made at least four starts.
"I think early in games that I am thinking about things a little bit because I want to make sure I get in a groove mechanically," Morton said. "I want to get things straight. As the game goes on, you just get more competitive and that takes over."
The Pirates' rotation is having its own competition. Their last eight starters have gone at least six innings, and seven of them have allowed one earned run or none after Francisco Liriano went eight while surrendering only two hits in Monday's 11-0 rout.
"Guys have different skill sets, different pitches," manager Clint Hurdle said. "More often than not we're pounding the zone. We're throwing strikes. We're changing speeds. We're moving things around, going to different locations. Their command and pace on the mound has played a big role."
Pittsburgh finally got going at the plate as well after totaling nine runs in its previous six games. Seven Pirates had multiple hits and Josh Harrison and Starling Marte had four apiece while occupying the top two spots in the order.
Marte has at least three hits in four straight games, becoming the first Pittsburgh player to do it since Willie Stargell in 1973. No Pirate has done it in five straight since at least 1914 and no major leaguer since George Brett's six-game streak in May 1976.
After coming into Sunday with by far the majors' fewest plate appearances against left-handers, Pittsburgh now faces a third straight southpaw starter with another - John Danks - to come Wednesday as this series shifts to Chicago.
First comes Jose Quintana (3-6, 4.00), whom the White Sox are hoping is over his awful start to 2015. With his ERA at 4.67 through nine outings, Quintana has posted a 2.21 over his last three.
His margin for error continues to be minuscule - Quintana's 2.66 run-support average is among the lowest in baseball - but he got enough help in Wednesday's 4-1 win over Houston while giving up one through seven innings.
"It feels good. Every time you wait for that," Quintana said. "But first you have to deliver a good outing and after that you wait for the support."
Quintana has never faced the Pirates - nor has Morton seen the White Sox (28-34) - but Marte figures to be happy to see him. Pittsburgh's left fielder has a 1.185 OPS against lefties in 2015, including five homers in 39 at-bats.
Chicago is hitting .199 during a five-game road losing streak and has been outscored by 58 runs while going 12-22 away from home.