MIAMI -- As committed as the Marlins were to retaining last year's core, the organization also recognized it had a small margin for error if it hoped to compete for a playoff spot.
From the outset, the breaks, along with a few crushing injuries, went against the Marlins. The low point was between April 19 and May 19, a stretch during which they went 6-21, and they spent the rest of the first half trying to rebound. They came close, finishing the first half with a sweep of the Giants at AT&T Park to head into the All-Star break at 41-4
The most historical moment in the first half was Edinson Volquezno-hitting the D-backs on June 3, but starting pitching struggles underlined the first half.

To the credit of manager Don Mattingly, his staff and the players, they stayed the course in the first half. Although they're far out in the standings, they've shown improvement, which has kept things interesting.
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What went right
The Marlins displayed huge power, reaching the 100-homer mark as a team before the break. Marcell Ozuna was voted an All-Star starter, and Giancarlo Stanton made the club as a reserve. Ozuna has played at a fringe National League MVP Award candidate level, and Stanton showed, when healthy, he's a force. Justin Bour was in the Home Run Derby, like Stanton. J.T. Realmuto has become one of the best and most athletic catchers in the game.

What went wrong 
In March, third baseman Martin Prado suffered a right hamstring strain while playing in the World Baseball Classic. It was a sign of things to come. Prado had two DL stints with the same injury. Left-hander Wei-Yin Chen has been out since April with an elbow issue. The rotation took a jolt when Tom Koehler and Adam Conley were both sent to Triple-A New Orleans. Koehler is back, but he's a trade candidate.
What we learned 
The organization's concerns that there wasn't enough starting pitching depth came to light. The plan was for the rotation to keep the team in games for five or more innings. But that hasn't always been the case, and the lockdown bullpen assembled was forced to log too many innings. Consequently, that unit has had its ups and downs. Offensively, Miami has shown the core can produce runs.

First-half top player 
Ozuna appears to be the real deal. An All-Star in 2016, many wondered if the 26-year-old would progress or regress. The questions were legitimate, especially after his second-half decline in '16. His bat speed and power are evident. If he sticks to his current approach, he should remain impactful.
First-half top pitcher 
Acquired from the Reds in January, Dan Straily was brought in to log innings and be a stabilizer in the rotation. He came as advertised, and the right-hander has been the most dependable and consistent starter. Opponents are hitting .210 against him and just .171 off his slider.

First-half top rookie 
Shortstop JT Riddle opened the season at Triple-A and was considered a utility infield possibility in case of injury. Now the 25-year-old from Kentucky is the everyday shortstop. His emergence helped prompt the Marlins' trade of Adeiny Hechavarria to the Rays for a couple of prospects.