"With the 19th selection in the first round of the 2009 first-year player draft, the St. Louis Cardinals select Michael Trout."--Bud Selig
This is fiction. The Cardinals indeed had this draft pick in 2009, and the young center fielder from New Jersey's Millville Senior High School was available. But rather than drafting Mike Trout, the Cardinals selected Texas high school pitcher Shelby Miller. Though according to Jeff Luhnow, Mike Trout was the backup plan.
And Shelby Miller has been a fine first-round pick. Only three players selected before Shelby Miller in 2009 have been more productive Major Leaguers by Baseball Reference Wins Above Replacement than Miller (#1 overall pick Stephen Strasburg, Mike Leake, and A.J. Pollock) and only one player among the 30 first rounders which followed Miller has outpaced him as a pro.
But make no mistake: with the gift of hindsight, there is no question that the Cardinals should have drafted Mike Trout. A solid pitcher who supplied two pretty good seasons in St. Louis before being traded for a one-year rental in Jason Heyward is more than most teams can say they drafted, but it is no comparison to a player who is, by WAR, the best player through age 24 since Ty Cobb.
Baseball Prospectus's Sam Miller has looked at projected Cardinals win totals with Mike Trout instead of Shelby Miller, and while it made for an interesting exercise to look at how Trout impacts the projected wins of 29 MLB teams, this doesn't account for how other moves the team makes are affected by the presence of the 21st century version of Mickey Mantle.
This is an estimation of what might have happened if the Cardinals selected Mike Trout.
After selecting Trout, considered neither a reach nor a steal, at #19, he is sent to rookie ball. With the presence of promising rookie Colby Rasmus, the Cardinals feel no need to rush what is considered a very good but not a generational prospect.
Things go essentially as they did with the drafting of Miller. The Cardinals still trade for Matt Holliday, as he can contribute to a 2009 stretch run in ways that Trout, 17 at the time of the Holliday trade, could not. And in the offseason, although Trout's prospect reputation increased thanks to a successful professional debut in 2009, he ranked only 85th on Baseball America's list of top prospects entering the 2010 season. This is nice, sure, but Trout's company on the list included such players as Jaff Decker, Adam Moore, and Lars Anderson. He was not a certainty to be great, or even good, and he was not expected to be either in the short term. As a result, the Cardinals still sign Matt Holliday to the seven-year, $120 million contract they did while drafting Shelby Miller.
Trout has a breakout 2010 season, which included a 173 wRC+ in A-ball during a season in which he turned 18 in August. Baseball America would rank Trout second only to Bryce Harper after the 2010 season. This was the season in which a decent-to-good prospect became a great one.
And to a degree, the moves the Cardinals actually underwent in 2010 work better if you assume they had an elite prospect in the minors. Their most notable in-season transaction, trading Ryan Ludwick for Jake Westbrook, makes even more sense if you assume that an outfield of Holliday, Rasmus, and Jon Jay will soon be supplemented by Trout. The transaction continues, and because Trout is still only 18, the results of 2010 hold.
Still happy with Rasmus, though perhaps willing to shift him over to right field when Trout arrives, the Cardinals still opt for a short-term fix in right field, Lance Berkman, while keeping Jon Jay as the fourth outfielder he was always projected to be.
With the Angels, Mike Trout made his debut in 2011 after an injury to Peter Bourjos, but the center fielders for the 2011 Cardinals stayed healthy, so that would not be where Trout would have a chance to break through. But he would still have a chance to break through.
After a rift between manager Tony LaRussa and Colby Rasmus developed, Rasmus was traded in late July. He was made more expendable due to the emergence of Jon Jay, who performed comparably to Rasmus. The problem is that the 2011 Cardinals suddenly became thinner in the outfield: Holliday-Jay-Berkman was workable, and Allen Craig handled the corner outfield spots admirably, but when Jay struggled, the backup plan was second baseman Skip Schumaker.
Because of this, Mike Trout makes his debut as a September call-up. He is serviceable, though nowhere near what he would become (in 135 plate appearances with the Angels, he had a below-average 89 OPS+ but played strong defense and was worth 0.7 WAR). The Cardinals still make the playoffs and still win the World Series, though Trout is mostly along for the ride.
Even more confident about their offensive depth, the Cardinals still allow Albert Pujols to leave in free agency and although Pujols is slightly more hesitant to go to an Angels team with less impressive minor league talent, he nevertheless still signs with them. With Trout still not considered fully ready, the team maintains its plan of signing veterans Berkman and Carlos Beltran.
Trout begins the season in AAA, and even following an April injury to Lance Berkman, he remains there, with Allen Craig taking over at first base. But following a shoulder separation in mid-May to Jon Jay, Trout is brought up to the majors, where he dominates. When Jay returns to the roster, the club sends Shane Robinson to Memphis while leaving Jay on the bench.
From May 15, the day on which Jon Jay went on the DL, until the end of the season, Mike Trout managed a .330 batting average, 28 home runs, and .976 OPS. An MVP-worthy stretch, but following a contentious debate about just how valuable a player can be in 3/4 of a season, he finishes 2nd to Buster Posey, while running away with Rookie of the Year.
Trout's excellence is not enough to win the NL Central: in reality, the Reds won by nine games and Trout was not a nine-win upgrade over Jon Jay. But the Cardinals are able to host the Wild Card game against the Braves, which they win, but with less fan animosity (fanimosity!).
The Giants won their NLCS victories by 5+ runs, so the presence of Mike Trout would not have likely changed the outcomes of any of these. The off-season is only impacted to a small degree: Lance Berkman's departure is even less crushing of a blow, the team still signs Ty Wigginton (I'm only granting the Cardinals improved foresight regarding Trout), and the Cardinals place only a superficial emphasis on re-signing Kyle Lohse.
Lacking Shelby Miller for the rotation, the Cardinals insert Joe Kelly into the fifth starter spot. Although he is a downgrade from Miller, Trout is such a sizable upgrade in center field that the Cardinals are easily a better team.
The formerly 97-win Cardinals clear 100 wins and Mike Trout wins his first NL MVP somewhat easily over Andrew McCutchen of the Pirates. Trout is particularly beneficial in the playoffs, where Jon Jay struggled and Shelby Miller almost literally disappeared. While I refuse to declare that the Cardinals would have won the 2013 World Series, their odds certainly would have improved, particularly in the quite close Games 4 and 5.
One of the big moves of the 2013-14 off-season for the Cardinals was trading David Freese and Fernando Salas for Peter Bourjos and Randal Grichuk, but this trade would never have happened in this alternate reality. Bourjos, and to a lesser extent Grichuk, were made redundant in LA by the presence of Trout, and the presence of Trout in St. Louis would change the Cardinals' demand for Bourjos.
But the team seemed intent on dealing Freese in order to make room for Kolten Wong. So rather than deal Freese and Salas for outfielders, the Cardinals trade Freese for a prospect. An example I pulled mostly out of thin air is trading Freese to the Cleveland Indians, who could have used an upgrade at third base, for catching prospect Francisco Mejia, who performed well in rookie ball as a 17 year-old. Mejia will not have paid any dividends through today, but he would give the Cardinals an option beyond Yadier Molina. The Cardinals will hold on to Fernando Salas as a back of the bullpen reliever.
The Cardinals will still sign Jhonny Peralta, but the most exciting transaction for the Cardinals in the off-season will be an extension signed by Mike Trout, under similar terms as the one he signed in reality with the Angels. And this time, it will earn praise about how Trout signed for less than market value because he wanted to play in Baseball Heaven for The Best And Most Knowledgeable Fans In Baseball (when in reality, it's a bit easier to lock down a player when you promise not to pay him the league minimum the next season).
To start 2014, the Cardinals will implement Yadier Molina, Kolten Wong, Jhonny Peralta, Matt Carpenter, Matt Holliday, and Mike Trout as regular starters with Allen Craig alternating between first base and right field, with Matt Adams and Jon Jay starting otherwise. Trout, of course, will continue to be a superstar; the 2014 season which was the worst to this point in his career was still good enough to win MVP unanimously in the AL, and although Clayton Kershaw would siphon some votes from him in the NL, Trout would still win his 2nd MVP.
As the season transpires, Allen Craig's decline begins. And while Mike Matheny stuck with Allen Craig until he was traded to the Red Sox, he would likely be more willing to go with Jon Jay than he was willing to go with Oscar Taveras, an uncertainty. The deadline deal of Craig and Joe Kelly for John Lackey continues, however, unabated: although Craig's bench role seemingly would make him a tougher sell, the Cardinals would not have to overcome his longer track record of poor results.
Although the lack of Shelby Miller does hurt the team's pitching depth, the offense is more potent. With Jon Jay shifted to right field, Trout represents a ten win improvement over incumbent options. Even accounting for worse pitching, the Cardinals would push 100 wins rather than settling at 90 and barely winning the NL Central, as they did.
After the death of Oscar Taveras, the Cardinals traded for Jason Heyward. This is probably off the table without Shelby Miller, and of course the Cardinals would not trade Trout for Heyward.
Entering the season, the Cardinals roll out the same lineup as 2014, but when Jon Jay struggles, the Cardinals promote Stephen Piscotty much earlier than his July 21 debut. Based on his production in 2015 and so far in 2016, while Piscotty may not have performed at 2015 Heyward levels, a combination of Piscotty and Mike Trout would certainly be more fortuitous than Heyward and whichever center fielder was being played at the time.
It's hard to improve upon a 100-win team. The addition of Mike Trout, finishing a respectable 2nd to Bryce Harper's mammoth 2015 with the Washington Nationals, would do just that.
So in the end...
Mike Trout would have improved the Cardinals. He has been the best player in baseball, by WAR, in three of his four seasons, and he was the second-best in the other. Even considering a lack of Shelby Miller or Jason Heyward, Trout makes the Cardinals better.
But the season results might not change. At least not dramatically. And that's the nature of baseball. Just as having a superstar the caliber of Mike Trout did not result in the Angels winning a single playoff game, the presence of Trout may not drastically have changed an already-excellent Cardinals team.