If you take a long enough view and accept a narrow enough range of acceptable outcomes, one can both-sides pretty much any baseball trade. For instance, last weekend’s visit from the San Diego Padres brought the return of Tommy Pham, whose departure from the St. Louis Cardinals via trade in 2018 was much-maligned and frequently criticized, including by this website. But while Pham is a reminder of the trade by his mere presence, and he was once a very valuable player, he is presently a thirty-three year-old with roughly an average bat who is largely relegated to a corner outfield position. A decent player, sure, but not somebody who would start on the Cardinals.

Tommy Pham’s absence most hurt the Cardinals in 2018, when the Cardinals missed the postseason by three games and Pham was a superstar with the Tampa Bay Rays, but would Pham have meant the difference in making the playoffs? Probably not–the Cardinals were 12 games above .500 in August and September with solid production from their outfielders, and while Pham would have helped, there was only so much he could have done. In 2019, Pham once again had a strong season, but he certainly wouldn’t have done enough in St. Louis to close the fifteen game gap separating the Cardinals from home-field advantage nor done enough to flip the absolute bludgeoning at the hands of the Washington Nationals into a series victory. And by 2020, Tommy Pham was no longer a significant contributor. Now, I am not personally a believer that the only trade worth making is one that leads to a World Series crown, so I still don’t like the Pham trade, but it is far more likely at this point that Genesis Cabrera or Justin Williams will contribute to a Cardinals World Series championship prior to reaching free agency than Tommy Pham would have.

The temptation in the aftermath of any trade is to look at the immediate dividends and assume that the future is too volatile to extrapolate. Often times, this is the case, but sometimes, you get the Cardinals trading J.D. Drew, Drew having an MVP-caliber season with the Atlanta Braves, and the trade being viewed in retrospect as a major win for the Cardinals because it brought back a prospect-aged Adam Wainwright. Evaluating trades isn’t as reductive as looking at each player’s total production–besides that Adam Wainwright’s production in 2021 would not come as a direct result of Adam Wainwright’s pre-free agency Atlanta Braves years, a six-WAR player is generally more valuable than two three-WAR players because it’s easier to eventually replace the less valuable players on the roster.

On July 29, 2018, the Cardinals traded for a pair of mostly unknown relievers and in return, they gave up an eventual league leader in home runs. This is a bit misleading–had either the Cardinals or New York Yankees properly evaluated the upside of Luke Voit or Giovanny Gallegos, assuming they did not have knowledge of how the other would turn out, they never would have made the trade. Luke Voit was regarded in the moment as a perfectly charming story, as a St. Louis area native who attended Missouri State University, but as a twenty-seven year-old first baseman with below-average MLB batting numbers while shuttling between Memphis and St. Louis, he was a very disposable prospect. And Giovanny Gallegos, nearly twenty-seven himself, had a mediocre 4.75 ERA in twenty MLB appearances with the Yankees and wasn’t even perceived in the moment as the definitively more important part of the return for the Cardinals, thanks to lefty reliever Chase Shreve.

Gallegos made two appearances in 2018 for the Cardinals, pitching well, but Voit went on an astonishing power surge for the Yankees, with 14 home runs in 148 plate appearances. He was almost immediately regarded as the first baseman of the future in the Bronx despite his lack of prospect pedigree prior to his arrival. While Voit wasn’t quite his late 2018 form in 2019, he did still manage a 125 wRC+, and while Giovanny Gallegos emerged as a significant bullpen contributor in St. Louis, the impact of a middle-of-the-order first baseman laps that of even an elite reliever.

A complicating factor in analyzing what Luke Voit could have done in St. Louis has long been the presence of Paul Goldschmidt. Even at Voit’s apex, Goldschmidt was always considered the more reliable player. But had the Cardinals not traded for Goldschmidt following the 2018 season, they would still have Carson Kelly, Luke Weaver, and Andrew Young. This three players wouldn’t be worth nothing to the Cardinals: Carson Kelly is an offensively superior catcher to Yadier Molina, Luke Weaver’s aggressively average starting pitching would have been considered a real asset during the weakest moments of the 2021 season for the Cardinals, and even Young, very much an afterthought when the trade was made, has been a shockingly solid second baseman/utility player. In a world where Voit is only a marginally inferior option to Goldschmidt, the improvements represented by Kelly/Weaver/Young would more than close the gap. But in 2021, Paul Goldschmidt has been substantially better–Voit has hit decently while healthy, but has battled injuries, while Paul Goldschmidt’s 132 wRC+ is more befitting of his last few seasons with the Arizona Diamondbacks than his relatively mediocre 2019 Cardinals debut. Meanwhile, Gallegos has been vital to the Cardinals, and with Alex Reyes and Genesis Cabrera wilting late in the season, Gallegos has become an increasingly pivotal component of winning late in the season.

Gallegos converted two one-run saves to solidify a three-game sweep of the San Diego Padres this weekend, but the louder hero of recent Cardinals vintage was also acquired via trade from a team that likely did not properly assess his value, in exchange for a player whose future success likely was not foreseen by the Cardinals. The July 2017 trade which sent Marco Gonzales to the Seattle Mariners in a one-for-one trade for O’Neill was a pure assessment-based trade: both teams were gravitating around .500 with minimal potential to reach October baseball, and with Gonzales unable to establish himself in St. Louis as a full-time player, the Cardinals sent him to the Pacific Northwest so that they could a flyer on Tyler O’Neill, the well-regarded Mariners outfield prospect.

Marco Gonzales did not pay immediate dividends for Seattle, not that he was expected to do so, but in 2018, he and fellow Cardinals castoff Mike Leake led the 89-win Mariners in innings. In 2019, Gonzales led the American League in starts, with 34, and in 2020’s abbreviated season, he improved in terms of production, with Major League Baseball’s best strikeout-to-walk ratio. And while Tyler O’Neill did pick up some hardware, winning the National League’s left field Gold Glove Award, his meager 70 wRC+ was the source of renewed angst that the Cardinals gave up Marco Gonzales for an outfielder whose greatest demonstrable skill seemed to be striking out.

But in 2021, Tyler O’Neill has been a revelation. His 28 home runs eclipsed his previous career mark, and his 139 wRC+ is the best on the Cardinals, all while remaining a viable Gold Glove candidate. And in the meantime, in Seattle, on a team that has remained on the periphery of postseason contention throughout 2021, with a regular starting outfielder with a 70 wRC+ in Jarred Kelenic, Marco Gonzales is in the midst of his worst season as a Mariner–his 4.05 ERA is passable, but his 5.31 FIP is very worrisome of things to come.

The St. Louis Cardinals are currently sitting three games ahead of the Cincinnati Reds for the National League’s second Wild Card, and it’s reasonable to guess that Tyler O’Neill being on the team instead of Marco Gonzales has made the difference. Does this mean that the Cardinals actually won the trade? Not necessarily, though this certainly helps the case. The Mariners were able to use their leverage with Gonzales to sign him to a modest extension through 2024, and if Marco Gonzales has a 2020-like season next year, this could change the calculus again. Neither Voit for Gallegos nor Gonzalez for O’Neill are unequivocal wins nor losses, and the full story of neither has been fully written. But we do know that the presence of Gallegos and O’Neill came very much in handy this weekend.

From the day Colby Rasmus was traded in 2011 to the Toronto Blue Jays until he reached free agency (i.e. when he also would’ve reached free agency with the Cardinals), he was worth 6.1 FanGraphs Wins Above Replacement. For the remainder of their Cardinals lives, Octavio Dotel, Edwin Jackson, Corey Patterson, and Marc Rzepczynski were worth 0.9 fWAR (the player Rzepczynski was later sent to Cleveland for, Juan Herrera, never made the Majors). And yet, as anyone who spent five seconds this weekend watching 2011 Cardinals nostalgia coverage knows, this is widely viewed as an all-time great trade for the Cardinals. Context matters. The Cardinals had a pressing need for pitching help on an otherwise borderline team, as well as a comparable Rasmus replacement lined up in center field, so the trade made sense, and it worked about as well as it possibly could have. If Giovanny Gallegos is the relief ace of a World Series champion this year, or if Tyler O’Neill comes up with the big World Series-winning hit, it will be a sealed deal whether their trades worked, though in the likely event neither happens, we will have to evaluate the positives and negatives. And whether the trade was good or bad will not have been decided in its immediate aftermath.