2010-11: Nikolas Koberstein played his first minor midget game with the Spruce Grove PAC Saints in suburban Edmonton as a 15-year-old; skating most of the season with the Saints bantam AAA team. He had no points nor penalties in that minor midget game. Koberstein played for the Northwest Sharks in the Alberta Cup and in five games had 2 assists. He was selected by Regina in the seventh round (135th overall) in the 2011 WHL Bantam Draft.
2011-12: Koberstein appeared in six games with the St. Albert Raiders midget AAA team in Alberta and played for the PAC Saints minor midget team. He had 3 assistst and 2 penalties skating with the Raiders. Koberstein scored 9 goals with 23 assists and 71 penalty minutes in 37 games with the Saints.
2012-13: Koberstein played in 34 regular season games and four playoff contests in his second season with the St. Albert Raiders. He scored 1 goal with 11 assists during the regular season and was scoreless with 4 penalty minutes in the Alberta Midget Hockey League playoffs.
2013-14: Koberstein joined the Olds Grizzlys in the Alberta Junior Hockey League and in November committed to playing at the University of Alaska-Fairbanks in 2015-16. He scored 5 goals with 13 assists and 153 penalty minutes in 51 regular season games. The Grizzlys finished seventh in the South Division; upsetting the second-place Okotoks Oilers in a first round series before falling to the first-place Brooks Bandits in the second round. Koberstein had 2 assists and 24 penalty minutes in nine playoff games. He was ranked 205th amongst North American skaters in the Central Scouting final rankings and was selected by Montreal in the fifth round (125th overall) of the 2014 NHL Draft.
2014-15: Koberstein skated in the USHL, starting the year with the Sioux Falls Stampede before being acquired by Bloomington in exchange for Cornell University-bound defensemen Matt Nuttle in January 2015. He scored 1 goal and was +11 with 75 penalty minutes in 30 games with the eventual USHL champion Stampede. Koberstein scored 3 goals with 8 assists in 31 games and was -1 with 63 penalty minutes in an increased role with the Thunder. Bloomington finished fifth in the Eastern Conference, nine points behind Muskegon for the final playoff spot.
2015-16: Koberstein skated in 23 games for Alaska-Fairbanks in his freshman season. He scored 1 goal with 1 assist and was -1 with 8 penalty minutes. The Nanooks finished eighth in the WCHA and were swept by Michigan Tech in the conference quarterfinals.
Koberstein is a gritty defenceman that plays a strong, defensive-minded brand of hockey. He is not an in-your-face type of defender that plays on the edgier side, but he knows how to mix things up and play aggressive. He has the ability to move the puck up the ice and join the rush, while keeping his position when needed and knowing when it is a good time to pinch. He has leadership and character qualities to his game, and he is always learning and improving. At the pro level, he could progress into a full-time NHL player if he can remain consistent, continue to play assertive, improve his skating and show a willingness to shoot the puck more.
Koberstein played for the University of Alaska-Fairbanks in 2015-16, skating in 23 of 36 games for the Nanooks as a freshman. A big, defensive defenseman who plays a hard game, Koberstein continues to work on his mobility, something that should get stronger playing on the Olympic-size ice sheet with the Nanooks. He is likely to use the rest of his NCAA eligibility before turning professional. He projects as a second or third pairing defenseman with a physical edge to his game.