First, a few ground rules. Having a breakout year is not the same as making a first impression. For example, Orlando City rookie forward Cyle Larin made a first impression with his 17 goals. But he didn't have a breakout year because he wasn't in MLS the year before.
Having a breakout year is also not the same as extending an upward trajectory. For example, Crew SC's Ethan Finlay extended his upward trajectory with his 12-goal, 13-assist season in 2015, which came on the heels of an 11-goal, 7-assist season in 2014. But he didn't have a breakout year because he had already broken out.
To have a breakout year, you had to be on the scene last year but not really make much of an impact until this year. It's kind of a backhanded compliment. Here is our breakout player of the year in MLS, as voted by the MLSsoccer.com editorial staff.
MLSsoccer.com's Breakout Player of the Year: Matt Miazga, NY Red Bulls
What a year Matt Miazga had in 2015. After making just seven appearances in 2014, the tall center back became a mainstay on the Red Bulls back line in 2015, playing in 30 games (regular season and playoffs) and finishing second among defenders in minutes played. He also scored his first goal (see video above) and proved to be one of the top aerial defenders in the league.
He also rose quickly through the ranks of the US national team. He started for the U-20 US team that reached the quarterfinals of the U-20 World Cup in May. Then he was one of the few bright spots for the Olympic qualifying team that failed to earn an automatic berth to Rio 2016. Finally, in November, he made his full USMNT debut in a World Cup qualifier against St. Vincent & the Grenadines. This month, he was named U.S. Soccer's Young Male Player of the Year.
Recently, there have been reports that Miazga could go abroad next year, and given his success in 2015, you can understand why the likes of EPL giants Chelsea and current EPL leaders Leicester City have been mentioned as possible suitors. But nothing is done, and we certainly look forward to seeing if he can extend his upward trajectory next year.
Kellyn Acosta, FC Dallas -- The smooth, 20-year-old box-to-box midfielder saw his minutes double in 2015, plus he scored his first MLS goal (and his second and third) and added a couple of assists. A favorite of our analyst Matt Doyle, Acosta also captained the US at the U-20 World Cup.
Tim Melia, Sporting KC -- Through his first five seasons, the 29-year-old goalkeeper played in six MLS games. In 2015, he started 23, solving SKC's frustrating goalkeeper issues. Along the way, he posted eight shutouts and was fourth in the league in save percentage.