– Hector Santiago’s first bullpen session of spring training was with new Twins catcher Jason Castro, and it didn’t take long for the lefthander to realize that he was paired with someone who likes to sell the strike.

“Usually you go through the motions,’’ Santiago said. “He’s back there holding pitches, framing them, grabbing the pitches and making sure he is working on his craft. You see the difference between the guy who just sweeps that pitch off the corner and throws it back to you and the guy who, boom, holds it for two seconds. Castro does a good job holding and showing you what your pitch is doing.”

Castro will be paid $24.5 million over the next three seasons, and not because he’s going to put up Mike Piazza-like numbers at the plate. It’s because of his defensive skill set, with pitch framing at the forefront.

Baseball has made breakthroughs in recent years in measuring glovework behind the plate, and Castro is among the best in the game at pitch framing.

Or stealing strikes.

Or fooling umps.

Call it what you want, but catchers with soft hands who can turn a wrist to make a pitch look like a strike are in demand.

“You are deceiving umpires,” said John Ryan Murphy, who hopes to be Castro’s backup. “That is part of the job.”

The new backstop

Castro, 29, was an All-Star in 2013 for Houston, but he hit just .215 over the past three seasons with below-average power. But last season, he got 96 more strikes called than expected, fifth best in baseball. He’s replacing Kurt Suzuki, who was popular among pitchers but had 38 fewer strikes called than expected. That’s a theoretical swing of 134 strikes in an area the Twins wanted to address.

Catchers such as Castro, Pittsburgh’s Francisco Cervelli and San Francisco’s Buster Posey are among the best in the game at framing pitches and influencing umpires. The subtle art is more than being still behind the plate and turning a wrist. As Castro explained it, there’s great importance in knowing what pitchers throw and how the pitches move so you can position yourself to accept the offering as cleanly as possible.

“At the end of the day, these guys are throwing 90-plus miles an hour and you are receiving that pitch and it is most likely going to pull your glove in one way or another unless it squares you up,” Castro said. “That’s the idea of trying to get your body behind the ball and counteracting the movement in which that ball would take your glove.”

Is it really worth obsessing over? Absolutely.

In 113 games last season, it’s a safe assumption that Castro caught at least 11,000 pitches — plenty of opportunities to change an at-bat, an inning or a game by selling a strike.

As an example: A 1-1 pitch is crucial. Last season opponents hit .268 off Twins pitching with an .845 on-base-plus-slugging-percentage after the count was 2-1. That dropped to .209 and .590 after it was 1-2.

“The consequences of a 2-1 count or a 1-2 count over the length of a season, that can have a pretty large impact,” Castro said.

And that’s where someone like Castro can impact an entire staff.

“That’s what you are hoping for,” Santiago said, “and that’s what the science was in getting Castro here so fast.”

Hard numbers

Castro, the 10th overall pick in 2008 by Houston out of Stanford, was introduced to pitch framing in 2013. That was one year after the Astros hired Mike Fast from Baseball Prospectus to head their analytics department. Fast, in 2011, was one of the first to write about the benefits of framing.

The catching position is vital. Calling games, controlling baserunners and handling crises have been the more traditional tasks, while framing has been underappreciated. But once Castro looked at the data, he was all in.

“I definitely enjoyed being part of that evolution and seeing both sides of it,’’ Castro said, “and seeing how much of a positive effect it could have if applied correctly.”

What has helped fuel the development of pitch framers? What else — statistics.

PITCH/fx and Trackman Doppler radar are systems that help track the movement, velocity, spin and location of each pitch. From there, it can be determined which pitches were strikes or balls — and if they were actually called strikes or balls. That’s how websites such as StatCorner have compiled pitch framing results.

Boom. There’s the hard data to motivate catchers to work on framing. The Twins now have Trackman at every minor league level above rookie ball.

“It is our goal as teachers and as instructors to use these stats to formulate a game plan to improve each catcher,” said Twins first base coach Jeff Smith, who has handled catching drills during spring training. “We have those stats, we have heat maps available that show the strengths and weaknesses of each catcher in the zone. We use those as teaching tools. Now we come out and get our daily work in and get better every day.”

Changing the call

The Twins have instituted new drills to help with framing. The goal is to help catchers develop soft hands and to move as little as possible while receiving pitches. Presentation, Smith likes to call it.

“When I was catching, if I moved my arm to catch a [borderline] pitch and the umpire saw it, that pitch was called a ball,” said first baseman Joe Mauer, whose clubhouse stall is next to Castro’s.

One drill is designed to help catch the outside part of the ball after it crosses the plate. That facilitates moving just a hand or wrist instead of an arm that could ruin the presentation. The less movement, the better — and the greater the chances of influencing umpires.

The Twins are behind some other teams in that they have not hired a minor league catching coordinator. Chief Baseball Officer Derek Falvey, leading a new regime that is expected to place extra emphasis on analytics, has indicated that the club intends to add one in the coming months. Until then, Smith will handle organizational catching coordination while with the major league team.

“Over the next year we expect to add more coordinators in catching and other fundamental areas to allow us to drill deeper,” Falvey said.

From the majors down through the minors, the Twins are investing more in catching development during a time in which pitch framing is being coveted more than ever.

A new emphasis

At spring training, catchers have been out for early drills, and they have held post-workout meetings into the midafternoon. Veteran Chris Gimenez, like Castro, has shared his experiences. Gimenez was with Falvey in Cleveland and with new GM Thad Levine in Texas.

“They have already created an environment where they’re pushing each other and learning from each other at the same time — that’s not common,” Falvey said. “My hope is that their work this spring and the attention to the fine details of the position makes each and every one of them better.”

This couldn’t have come at a better time.

Mitch Garver is the Twins’ best catching prospect and reached Class AAA Rochester last season. He was an offense-first draftee out of New Mexico in 2013. He slowly has developed into a solid defensive catcher who threw out 48 percent of baserunners attempting to steal last season. This spring, his coursework includes pitch framing drills.

“Framing came along about five years ago but it didn’t get really get big here until we signed Castro,” Garver said. “We didn’t do a lot of these things before, but now we are. And I like it. It has made a big difference for me so far and it’s now a matter of continuing the process.”

The Twins also spent a second-round pick last year on Ben Rortvedt, a catcher from Verona, Wis., who will get to benefit from the Twins’ new view of building a better catcher.

“Because of innovations in technology it’s become another tool that we can use to better understand a catcher’s defensive value and the impact it could have on a pitching staff,” Falvey said, “but I’d argue that this is always something that’s been a part of the game — we can just quantify it better now.”