The World Championship opened his eyes too.
Seider, No. 6 on NHL Central Scouting's final ranking of International skaters for the 2019 draft at Rogers Arena in Vancouver on June 21-22, has seen how far he's come, and how far he has yet to go.
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"There's a big gap between me and the NHL," the 18-year-old said following Germany's 5-1 loss against Finland in the quarterfinals at Ondrej Nepela Arena in Bratislava, Slovakia, on Thursday. "You have to be serious. For sure, it's still for sure a couple of years. You have to be realistic and work on those things and get prepared."
The World Championship has given Seider a base to build on, and he could become the highest-selected German-born player at the NHL Draft since the Edmonton Oilers selected forward Leon Draisaitl No. 3 in 2014.
"Seider is a powerful player with very good overall skills," said NHL director of European Scouting Goran Stubb. "Strong, mature, skilled and a solid two-way player. Effective in all situations. Good hockey sense and plays an effective simple game."
Seider (6-foot-3.5, 183 pounds) missed three games of the World Championship because of an injury sustained in the round robin but had two goals in five games and averaged 13:47 of ice time per game -- fifth-best among defensemen for Germany -- in the tournament.
He impressed in his brief showing.
"He plays like a 35-year-old, almost," said Draisaitl, teammates with Seider at the World Championship. "He's so calm and so collected. It's pretty fun to watch. Hopefully he keeps developing the way that we think he will and you know he's going to be a special player.
"It's great to have a young kid coming up that seems to have the potential to be very, very good at hockey."
Seider's rise in German hockey has been sharp. After helping Jungadler Mannheim to a Deutsche Nachwuchs Liga title in junior last season, the right-shot defenseman won a Deutsche Eishockey Liga championship, Germany's top professional league, with Adler Mannheim in 2018-19. He had six points (two goals, four assists) and was named the league's rookie of the year despite being limited to 29 games because of a shoulder injury.
On the international stage, Seider captained Germany to victory at the 2019 IIHF World Junior Championship Division 1A, returning his country to the main group for the 2020 World Juniors. He was named the tournament's top defenseman after leading his position with seven points (one goal, six assists).
"It all went pretty fast, the last couple of years," he said. "I came to Mannheim just four years ago just to play under-16 and jumped to under-19 and now I'm standing here at the World Championship and playing in a quarterfinal. It's an unbelievable season."
The impression that he left will last longer than the sting of losing in the quarterfinals.
"I saw him play a couple times just watching some of the playoff games from back home, and then the first hand saw him when I went to Munich to the semifinal against Mannheim," said Germany defenseman Korbinian Holzer (Anaheim Ducks). "After that I met him the first time here with the national team. Obviously you can tell he's a really good player, very smart, very humble.
"He looks way older than 18. He plays way older than 18. He's really humble, really relaxed it seems, in his own zone. He isn't afraid to join the rush. He looks very comfortable out there. You can tell, for an 18-year-old, he definitely plays bigger than his age."
NHL.com staff writer Mike G. Morreale contributed to this report
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