"We're still learning about these guys," Ron Gardenhire likes to say about his starting rotation, which is currently made up of four pitchers who weren't Twins a year ago.

Thanks to 3 inches of snow and 35 degrees of wind chill, he learned a little more about the most and least successful of the newcomers thus far — all on one long, shivery Tuesday at Target Field.

Kevin Correia pitched seven effortless innings in the afternoon game, retiring 10 of the final 11 hitters he faced, in backing Oswaldo Arcia's first career home run as the Twins collected their fifth consecutive victory, 4-3 over the Miami Marlins. Correia, a former Pirate who signed a two-year deal as a free agent last winter, has been uniformly effective in all four of his starts, giving him Minnesota's most effective April since 2007 and slimming his ERA down to 2.86.

Mike Pelfrey has also been consistent in his four starts as a Twin, and that's been far less encouraging. The former Met, still less than a year removed from elbow-ligament replacement, threw 94 pitches and couldn't finish the fifth inning of the night game, an eventual 8-5 loss.

Correia has delivered four quality starts in four attempts. Pelfrey is 0-for-4.

"I'm extremely frustrated. I worked so hard to get back from this injury, and I feel good. But it just hasn't been too pretty," Pelfrey said. "I haven't been good yet."

Especially at the beginning.

Pelfrey's ERA climbed to 7.94 in his first four starts as an American Leaguer, and he allowed three more first-inning runs, giving him nine — out of 15 runs he's surrendered altogether — in four games, or a first-inning ERA of 20.25. On Tuesday, he loaded the bases almost immediately, then just missed escaping when a double-play relay was a half-step late. The next batter, Rob Brantly, knocked a two-run double off the wall, and Pelfrey was in an early hole — one the Twins would not escape — for the third time in April.

"A lot of deep counts, a lot of pitches early in the game," Gardenhire said. "We hope we start seeing him progress. He's trying. He's doing everything he knows how to do. But you get strike one, then get a 3-2 count — we've got to do better than that."

He needs to be more like Correia, in other words. The veteran righthander has yet to deliver anything but seven strong innings, and his pitch counts are all between 101 and Tuesday's 87.

The last Twins starter to last seven innings in his first four starts was Ramon Ortiz, six years ago.

"He's able to spin the ball, [and he] changes it up on hitters. He doesn't get too many patterns," Gardenhire said after Correia's second victory of the year. "He can kind of loop a curve in there. The secret is, he's ahead in the count so many times and making [hitters] have to be defensive."

The Twins hitters were aggressively offensive in backing up Correia, with three consecutive first-pitch hits turning into the game-winning runs. Chris Parmelee opened the fourth inning, with Minnesota trailing 4-2, by lashing the first pitch he saw into center. Trevor Plouffe sent Jose Fernandez's next pitch into center as well, and Arcia, the Twins' young Venezuelan slugger, came up with an idea.

Parmelee and Plouffe had both hit fastballs, "so [I] looked for a changeup," Arcia said through interpreter Wilkin Ramirez. "[I] knew it would be something off-speed."

It was, but only until Arcia swung. Then it sped rapidly onto the right-field plaza, making him, at 21 years old, the youngest Twin since Joe Mauer in 2004 to hit a home run. "That's the farthest I've seen a ball hit this year," Correia said.