The Toronto Blue Jays had little trouble figuring him out on Tuesday night.
The Jays got to Vargas for six runs in the first inning and went on to a 13-7 victory.
It's been an inconsistent season for Vargas. He has had moments of brilliance with three complete-game shutouts and another scoreless nine-inning no-decision.
He also lost five straight starts in July, working beyond six innings just once.
Then in his previous start against Texas, he went seven innings and allowed three runs in a 4-3 victory.
Vargas (7-11) responded with four innings against the Jays, allowing seven hits and eight runs.
"You definitely can't let that team score that many runs off you in the first inning and expect to keep your team in the ball game," Vargas said.
Yet the Mariners fought back. After the Jays' six-run first — highlighted by Colby Rasmus three-run double — the Mariners rallied.
For Wells, it was his fourth home run in his fourth straight game. That matched Danny Tartabull for the Mariners' rookie record. Tartabull hit his four straight April 12-15, 1986.
"I'm not going to bed thinking about trying to hit a home run tomorrow," Wells said. "I'll go up with the same approach and hopefully get some mistakes from the pitchers."
Miguel Olivo followed with a home run over the left-center wall, the fourth time this season the Mariners have had back-to-back home runs and second time in two nights.
Eight batters went to the plate in the third as the Mariners scored three more to tie the game. Trayvon Robinson hit a two-run single and Kyle Seager tied it with an RBI single.
But Vargas and the bullpen gave it up again.
Jose Bautista opened the fifth with a walk and Adam Lind singled, ending Vargas' night. Tom Wilhelmsen, who earned his first big league win Monday, took over and walked Edwin Encarnacion to load the bases.
Wilhelmsen's next pitch caromed off umpire's Tim McClelland shin and into the Mariners' dugout. Bautista walked home on the wild pitch.
Rasmus and Aaron Hill each added a sac fly and J.P. Arencibia had an RBI single to build the lead to 10-6.
Rasmus had four RBIs, his most since coming over in a July 27 trade with St. Louis.
Hill, who had a two-run home run in the first, matched his career high with four RBIs.
Bautista hit a two-run home run in the sixth, his major league-leading 35th. It was estimated at 438 feet.
"Vargas was off a little early and over the plate," Mariners manager Eric Wedge said. "It is a good hitting ball club, but he was able to come back and throw up some zeros."
He best zero-maker, however, was Jays reliever Luis Perez (2-2). In a game with 20 runs and 26 hits, he stood out for his ability to stop the Mariners.
He matched his career high with four innings, allowing three hits, one run, two walks and striking out three.
"The four innings by Luis Perez are probably the story in tonight's game," Jays manager John Farrell said. "It looked like it was going to be one of those nights when we couldn't score enough. The ball was carrying here uncharacteristically. It was a good overall effort from Luis.
"Once we took the lead again it was Luis who set the tone as was able to stabilize the game for us on the mound."
The Mariners had a two-out rally in the fifth with runners on first and second. Ichiro Suzuki bunted and was easily thrown out.
"I've already talked to Ichy. I still want him to swing the bat right there," Wedge said. "I know he's trying to keep the inning going. He felt like the third baseman was back, and he tried to keep the inning going.
"That situation with two outs I want him to swing the bat so we talked about it."
Carp extended his hitting streak to 16 games with a single in the third. He's hitting .385 with four home runs and 18 RBI during the streak. He entered the game with the most August RBI in the majors with 17.
Notes: RHP Jon Rauch gave the Jays medical staff little warning before Monday's game that he would eventually have to have an appendectomy Tuesday morning. "Before the game he felt some stomach discomfort. But he checked out OK and certainly felt he was capable of pitching," Jays manager John Farrell said. "Then after the game things began to intensify a little bit and at that point we felt like it was time to get him checked." Rauch was placed on the 15-day DL. LHP Trever Miller also was designated for assignment and two lefties, Wil Ledezma and Rommie Lewis, were called up from Triple-A Las Vegas. ... An MRI has revealed that OF Rajai Davis has a hamstring tear. Farrell said for Davis' mindset "our goal is to get him back on field before season's out." ... With the last-minute signing Monday of first-round pick, LHP Danny Hultzen, the Mariners also agreed to give him a big-league contract. Room needed to be cleared on the 40-man roster so RHP Chris Ray, on the DL with a right shoulder strain, was released. ... RHP Brandon Morrow (8-7, 4.55), traded to the Blue Jays two years ago, finally makes his first start against his former team at Safeco Field Wednesday. "I think anytime a player comes back to his original organization, there's going to be some added adrenalin, maybe some emotion," Farrell said. ... The Mariners will send out RHP Blake Beavan (3-3, 3.39), acquired in the Cliff Lee trade with Texas last season.