Jamtin was born Stockholm, Sweden but he spent the first two junior years with Farjestad. He started the 2000-01 season very well with 13 points in the first 13 games. He also picked up 83 PIM in a league that isn`t very rough.
Jamtin was suspended by the club for disciplinary reasons, and he decided to leave for Stockholm where he joined AIK`s organization.
He couldn´t continue his season with AIK due Swedish regulations, but he still made the Swedish World U-18 team and displayed great talent throughout the whole tournoment and finished as the best scorer on the team with 7 points (3+4) in 6 games, and as usually he spend some time in the penalty box, 26 minutes.
Jämtin spent the 2002-03 season in Allsvenskan after making his debut in Elitserien the previous year. The demotion served him well as he excelled offensively on a young AIK-team.
Jämtin ended the year with 25 goals and 46 points in 56 games. He also led the team in +/- with +22 and was also the leading player in penalty minutes with 145.
During the season Jämtin was also selected to participate at the WJC where he was expected to be one of the leaders on the team. In the pre- tournament games he fulfilled the expectation, but as the real tournament started, Jämtin wasn´t as effective. With only one goal and 5 points in 6 games Jämtin´s performance was a disappointment.
Jämtin attended his second mini-camp for prospects with other Red Wings draftees. And for the second time he displayed his pro-style game as he was one of the best players at the camp.
Jämtin is a very good skater who has great speed and quickness. He is a very aggressive forechecker who likes to get under the skin of his opponents. Although not being overly big Jämtin is a capable hitter who enjoys this aspect of the game. He posseses very soft hands and is able to make things happend offensively. Jämtin is also a smart player who has very good on-ice vison which makes him a dangerous offensive threat. Jämtin has developed his defensive game and is now a reliable two-way player who plays with an edge. He posseses a good arsenal of shots where his wrister is his main weapon because of its accuracy and hardness.
Assigned to the ECHL Charlotte Checkers to begin 2008-09.