Kansas City Royals starting pitcher James Shield. (AP)

Baseball may look back on 2014 as the year the prospect bubble expanded to its bursting point.

It took years to reach this point. Teams commodified the future, selling promise when they couldn’t sell success. Fans, many of them driven by fantasy leagues, delved deeper into farm systems, digging for information and future stars. Annual prospect rankings exploded in number, grew in popularity and sprouted midseason and post-draft updates. The Next Big Thing became the only thing.

To a point, the cycle happened for good reason. Baseball’s salary structure makes young talent the cheapest and easiest to control. Prospects add excitement to a tradition-steeped sport with a marathon season. They’re evolving lottery tickets. Teams once swapped high-ceiling minor leaguers for established veterans with disregard. As recently as 2008, the Orioles rebuilt themselves with one trade, sending Erik Bedard to Seattle for Adam Jones, Chris Tillman and other pieces.

What’s happened in the years since, though, is an over-correction and the formation of unrealistic expectations. In June, Sports Illustrated used its cover to label the Houston Astros, who have gone 216-398 since the start of 2011, as “Your 2017 World Series Champs.” Prospect rankings had become a way not just to gauge progress, but to define success.

Teams have started swinging the pendulum back closer to reality. In the offseason before the 2013 season, the Royals were savaged for trading prospects Wil Myers and Jake Odorizzi to the Rays for James Shields and Wade Davis, a right-hander who swung between the Rays’ rotation and bullpen. It was framed as a smart organization robbing an old-fashioned one: Six years of future star Myers, plus the upside of Odorizzi, for two seasons of Shields and a spare part.

Look now. The Royals flirted with the playoffs last year, and this season they lead the American League Central. Shields is their leader. Davis might be the best reliever in the American League. The Rays went to the playoffs last season as Myers won rookie of the year. Myers has struggled through growing pains and injury this season, and the Rays are in fourth and currently out of the race, even as Odorizzi establishes himself as a solid starter.

Below the Rays in the AL East lies another cautionary tale for placing too much faith in prospects. After winning the World Series in 2013, the Red Sox plugged rookies Xander Bogaerts and Jackie Bradley into their starting lineup. Bogaerts is hitting .224 with a .627 OPS. When the Red Sox demoted Bradley recently, he was slugging — slugging — .290.

At the trade deadline this season, A’s General Manager Billy Beane traded his best prospect, shortstop Addison Russell, to land pitchers Jeff Samardzija and Jason Hammel. At the time, he called the present an undervalued asset. Teams in his estimation had started hoarding prospects too much.

Of course, many high-rated prospects work out just as teams hope and analysts predict. Yasiel Puig rescued the Dodgers last season. Where would the Nationals be without Anthony Rendon? But that’s part of the point. No matter where they show up on a prospect list, young players succeed and fail for myriad reasons.

Veterans at least provide a track record to help predict their future success. Prospects can be scouted and tracked, but at the end of the day, they offer little more than hope. That hope remains an extremely valuable commodity, as it should. But after this season, the hype and expectation attached to prospects may dial back a bit.