Kirby Puckett had two Major League seasons and more than 1,300 plate appearances when it happened. It all came together for the Twins slugger, and he then put together 10 of the best seasons any player has ever had.

Bryce Harper had a similar experience -- he didn’t flirt with greatness until his fourth season. Clayton Kershaw already had 83 starts and three seasons when his true greatness emerged.

Breakouts are happening all over the Majors this season, as well. If you’re wondering why projecting postseason races is so difficult, this is a good place to start.

Here are nine notable breakout seasons:

1. Gio Urshela, 3B, Yankees: The Yankees did not precisely know what they were getting when they purchased Urshela from the Blue Jays in August. Where Toronto saw the then-26-year-old as expendable, New York general manager Brian Cashman saw him as a really good defensive third baseman, with the potential to do more offensively. In short, organizational depth. His rise to stardom -- .850 OPS, Gold Glove-caliber play at third -- has been as improbable as anything in recent seasons.

2. Paul DeJong, SS, Cardinals: DeJong hit 25 home runs and finished second in the National League Rookie of the Year Award voting two years ago, and because he’s still only 25, there was room for growth. In his third season, DeJong's strikeouts are down, his walks are up and his defense is as solid as ever. In short, he’s a complete player and he is playing his way onto a bunch of NL MVP ballots.

3. Rafael Devers, 3B, Red Sox: Devers debuted at 20 years old in 2017 and endured two seasons of the highs and lows that many young players go through. What has emerged in 2019 is a special player. In that way, he has become just what the Red Sox always projected him to be.

4. Joey Gallo, CF, Rangers: Gallo was once one of the most heralded prospects in baseball, and the Rangers believed they had their next great player when he debuted four years ago. He’s now all of 25 years old and he began this season with 1,262 plate appearances. Gallo's path to stardom has not been a straight line. But in his fifth season, he’s a complete player and is starting to surpass even the most optimistic projections.

5. Josh Bell, 1B, Pirates: Bell completely remade his swing mechanics during the offseason -- but stop us if you’ve heard this one a time or two already. He began the weekend tied for ninth among hitters in the NL in Fangraphs WAR (2.0), and his 16 home runs were four more than he hit all last season. Bell is very much in the MVP conversation with Christian Yelich, Cody Bellinger, Javy Baez and others.

6. Lucas Giolito, RHP, White Sox: Give White Sox general manager Rick Hahn credit for patience through a three-season learning curve in which plenty of people wondered if Giolito -- the centerpiece of the Adam Eaton trade with Washington in 2016 -- would ever connect all the dots between great stuff and great performance. His shutout of the Astros on Thursday was a coming-out party for a guy who has a 1.35 ERA in five starts this month.

“He was doing really anything he wanted to,” Astros manager AJ Hinch said. “He’s changed his delivery, his arm action a little bit. He came in and really commanded the game from the very beginning.”

7. Martín Pérez, LHP, Twins: Sometimes, a guy needs a change of scenery and maybe a new approach to things. Perez was signed by the Rangers at 16 and he was in the big leagues at 21. This season, things have clicked in a way they seldom did during 128 starts for the Rangers. The Twins cannot get enough credit for identifying the potential in Perez and then helping turn it into performance.

8. Hunter Dozier, 3B, Royals: To Royals manager Ned Yost, this breakthrough season isn’t all that complicated. In Dozier, Yost sees a player who finally trusts his ability, who doesn’t overthink things and who is growing day by day into the cornerstone-type player the Royals envisioned when they made him the eighth pick of the 2013 Draft. He’s on track for a 30-double, 30-homer, 80-walk season.

9. Zach Eflin, RHP, Phillies: Eflin has ridden a new cutter and a commitment to pounding the strike zone and pitching to contact to a tremendous start. If he can sustain it, he would tremendously boost the Phillies' pursuit of the postseason. Among qualified NL starters, Eflin has the fifth-lowest ERA (2.76) and a respectable 1.15 WHIP (14th).