CHICAGO – An organization’s best moves are often the least noticed. That was certainly the case during Theo Epstein’s tenure with the Red Sox, a notion that was reinforced on Saturday night by Boston’s 4-3 victory over Epstein’s current club, the Cubs.

Front-and-center in the victory was Jarrod Saltalamacchia, who went 2-for-3 with a home run and double while improving his OPS to .835 (tops in the American League among catchers with at least 150 plate appearances) and his home run total to 12 (most in the majors by a catcher).

On the day that Saltalamacchia was acquired by the Red Sox for three prospects on July 31, 2010, at a time when he was with the Rangers’ Triple-A affiliate in Oklahoma City, the move was deemed relatively insignificant. Indeed, that day, Epstein spent time after the passing of the trade deadline fielding questions about why the Red Sox -- at that point, a team on the outskirts of contention -- did not make a trade deadline move.

The Saltalamacchia deal was not without cost. The Sox had to give up a young right-handed pitcher with an electrifying arm in Roman Mendez, a 21-year-old who has struck out more than a batter an inning in his minor league career. Still, for a frontline starting catcher whose rights the Sox would retain through 2014, the decision to buy low on a catcher with massive raw power who’d fallen out of favor in the Rangers organization was irresistible.

And then, there was the landmark deal of the Epstein era, the one that arguably played the biggest role in the team’s two titles of the past decade. That was the signing of free-agent David Ortiz, roughly one month after he’d been released by the Twins, to a one-year, $1.25 million contract, a deal that continues to impact the Sox after 10 years.

Of course, the unpredictable nature of buy-low deals is reinforced by Ortiz’s earliest distinct memory of a conversation with Epstein.

“When I wasn’t playing, I told him to release me or trade me, because I was better than the other guys he had here,” Ortiz said, recalling a time in May 2003 when the Red Sox had a logjam of five players -- alphabetically, Jeremy Giambi, Shea Hillenbrand, Kevin Millar, Bill Mueller and Ortiz – in May. “He told me to give it some time, he’d make some moves, then I would play. And then I started playing and here I am still.”

Epstein’s recollection of the conversation with Ortiz and his agent, Fern Cuza?

“When when we had Hillenbrand and Giambi and Bill Mueller and Millar and him, let’s just say he wasn’t getting the first crack at playing time. He and his agent asked for a trade,” the Cubs president of baseball operations recalled at Wrigley Field. “I said, ‘Hold on, we’re going to make a trade, but it’s not you -- it’s so you can go play.’

“Then we made the trade and I said, ‘All right, go out and do your thing.’ Then he went off.”

At the time that third baseman Shea Hillenbrand was dealt to the Diamondbacks in exchange for Byung-Hyun Kim, Ortiz had played in 30 of the team’s first 52 games. He was hitting .273 with a .354 OBP, .444 slugging percentage and .798 OPS with a pair of home runs.

“We knew we needed a reliever and we knew there were too many bodies,” said Epstein. “He hadn’t hit for any power at that point. We knew that we wanted to see what he could do. We didn’t know he was going to turn into Big Papi.”

With Hillenbrand out of the mix, Ortiz’s playing time gradually increased, until he became a lineup fixture by the end of interleague play. And it was then that he emerged as an improbable superstar, a player who was a castoff from one organization (two if you count a Mariners team that had dealt him for Dave Hollins in Sept. 1996) and who had requested his departure from the Sox before he became one of the greatest hitters in franchise history.

Ortiz quickly realized that he wanted to remain in Boston, and the Sox were happy to comply. After he avoided arbitration in 2004 by signing a one-year, $4.5875 million deal, he signed his first long-term deal with Epstein and the Sox during the 2004 season, a two-year, $12.5 million extension for 2005-06.

“I was fine here, but they knew that they were getting a bargain,” said Ortiz. “Even with my second extension (a four-year, $52 million deal that was reached in 2006, covering the 2007-10 seasons, with a $12.5 million option for 2011), they knew they were getting a good deal, for a guy putting up numbers like I was. You don’t get that [performance] anywhere.

“Me and the Red Sox got a good package. It turned into a long-term deal with myself.”

It continues to pay dividends even now, at a time when he is under contract on a one-year, $14.575 million deal, a figure that allowed the Sox and Ortiz to avoid arbitration prior to this year. To date, he is living up to his end of the deal. He went 1-for-2 with a double and two walks on Saturday, and he is now leading all designated hitters in average (.308), OBP (.392), slugging percentage (.586) and OPS (.978).

At a time when Adrian Gonzalez is slumping, he is the most feared hitter in the Red Sox lineup, the one whom opponents are circling and approaching with extreme caution, often walking him rather than attacking the one Sox hitter who has been doing consistent damage all year. That production has Ortiz once again confused about the fact that the Red Sox have shown little impetus to pursue a long-term deal with him, but the 36-year-old says that he is beyond worrying about the phenomenon.

“I just still don’t understand why it’s so hard for them to give me a two-year deal now,” said Ortiz. “I talked to [Epstein] about it last year, and he obviously doesn’t want to do it. It was pretty obvious. … It doesn’t bother me any more because it’s just going to cost them. It’s not my problem anymore. It’s their problem.”

Obviously, that prospect is far removed from the origins of the Red Sox’ relationship with a player whom they signed to perhaps the most important deal in franchise history. But at a time when the Red Sox are visiting with Epstein, the man who signed Ortiz, it is worth remembering the extraordinary – and unlikely – beginning of the designated hitter’s tenure with the Sox, a single, unheralded deal that transformed the franchise for the next decade.