There wasn't much technical expertise required for John Jaso in explaining his latest "professional at-bat" that pretty much decided this game one inning in.

Jaso is far and away the template for what the Mariners want every at-bat from their hitters to look like. But his three-run homer in the opening frame of Friday's 6-1 win over the Kansas City Royals was more a case of see-bad-pitch, hit-bad-pitch on a 96 mph cutter right down the middle.

The Royals so far have thrown the equivalent of batting practice to the Mariners in two games here, allowing some of Seattle's struggling hitters to play catch-up to Jaso in terms of results.

"I was looking for a ball up and something I could get to the outfield," said Jaso, who drove in four runs on the night. "That's just what I got, and luckily I put enough barrel on it to get it out."

Truth is, the way the Royals have pitched to the Mariners in six games this season makes the job a lot easier for guys like Jaso and company.

With runners at the corners and one out in the first, the only thing Jaso wouldn't want to do is hit the ball on the ground where he could be doubled up. But when Royals starter Jeremy Guthrie fell behind 1-0 in the count, he gave Jaso the luxury of sitting on a fastball he knew was coming.

And when Guthrie sent it in belt-high, there was no doubt where the ball was going to land once Jaso swung at it. The crowd of 14,953 of Safeco Field knew the ball was out the moment it left Jaso's bat, and yet another dismantling of a Royals starting pitcher was under way.

"If you look at his at-bats," Mariners manager Eric Wedge said, "that's what we're looking to do with all of our guys."

Mariners starter Blake Beavan cruised through 6-2/3 problem-free innings from there, striking out six.

The Mariners have scored 41 runs in six games against the Royals the past 11 days. They have scored just 45 against all other teams the rest of July.

Kansas City's pitching staff, which was weak to start the season, has lost two starters and two relief pitchers to "Tommy John" ligament-transplant surgery. Guthrie was traded to the Royals last week for Jonathan Sanchez, whom the Mariners knocked off Kansas City's big-league roster a week ago.

The subpar pitching has allowed several struggling Mariners to give their stats a boost. Mike Carp is now hitting .186 and followed his three-hit performance on Thursday with two more, including a sixth-inning homer off Guthrie to cap Friday's scoring.

Brendan Ryan had two more hits to boost his average up to .195 as he tries to break back through the Mendoza line. And Dustin Ackley — in an 0-for-20 slump to begin the series — also had a run-scoring double.

"I really feel like my swings haven't been that different in the last week," Ackley said. "It just feels like I've squared these balls up as opposed to missing them."

The Royals, on the other hand, got their only run in the second inning when Billy Butler — the only Royals hitter who's shown up this series — scored on a sacrifice fly by Salvador Perez.

Beavan decided to shelve his "terrible" curveball from there and just used fastballs and sliders to dispose of the anemic-looking Royals.

"I made some pitches and got some fortunate outs right to people," Beavan said.

Wedge felt that Beavan's fastball had some extra life to it. But he seemed even more pleased to see his team's bats come to life for a second straight night.

It may only be against the Royals. But after spending weeks telling the Mariners they'd be rewarded for a more solid, Jaso-like approach, Wedge at least got to see his hitters reap some rewards before facing more challenging pitchers.

"If you do that, over time it's going to pay for you," Wedge said. "I think our guys are working in the right direction offensively."

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com