Steffen Sontheimer grew up in the German town of Gernsbach. Details of his early childhood are limited, but it is known that he pursued higher education in industrial engineering at the Karlsruhe Institute of Technology. During his studies, Sontheimer developed a strong interest in poker, even writing a dissertation related to behavioral economics in poker, indicating an early analytical approach to the game.
Sontheimer began his poker career playing online cash games under the alias "go0se.core!" on PokerStars, where he achieved the prestigious Supernova Elite status for two consecutive years. He also played on PartyPoker as "Partygo0se". His decision to become a professional player was cemented during a trip to Canada in May 2014 to participate in the Spring Championship of Online Poker (SCOOP), alongside notable players such as Reiner Kempe and Fedor Holz.
Sontheimer’s live tournament debut came in the summer of 2015. By 2016, he had progressed to competing in high roller tournaments. His breakthrough year was 2017, when he won the inaugural Poker Masters Purple Jacket, securing $2,733,000 in prize money. That same year, he won tournaments with $50,000 and $100,000 buy-ins and was a runner-up in a $100,000 buy-in event, earning over $1.2 million. In 2018, Sontheimer claimed victory at the Caribbean Poker Party $250,000 Super High Roller Championship, earning $3,685,000, further solidifying his status in the high-stakes poker world.
He is also known for mentoring fellow players, such as Kitty Kuo, and is described as a formidable "crusher" in the poker community. In addition to playing, Sontheimer is a shareholder in No Limit Gaming, an esports organization founded by Stefan Schillhabel, and regularly streams poker content as part of the NoLimitGG poker and esports team.
As of August 2020, Steffen Sontheimer ranks sixth on the German all-time money list, with career live tournament winnings exceeding $13.7 million.
Sontheimer maintains close friendships with several prominent German poker professionals, including Fedor Holz and Stefan Schillhabel. He has also been neighbors in Vienna with Linus “LLinusLLove” Loeliger, another notable poker player, though they are not particularly close.
Throughout his career, Steffen Sontheimer has amassed over $13.7 million in live tournament earnings. His most significant single cash was the $3,685,000 prize from the 2018 Caribbean Poker Party Super High Roller Championship. His consistent success in high roller events has made him one of the highest-earning German poker players.
Steffen Sontheimer is regarded as one of the most skilled and successful German poker players of his generation. His rapid rise from online cash games to dominating high roller live tournaments has inspired many aspiring players. His involvement in esports and poker streaming also bridges traditional poker with modern digital entertainment, contributing to the evolving landscape of professional poker.
Sontheimer became a professional poker player in May 2014 during a trip to Canada to compete in the SCOOP tournament series.
His major achievements include winning the inaugural Poker Masters Purple Jacket in 2017 and the Caribbean Poker Party $250,000 Super High Roller Championship in 2018. His career live earnings have exceeded $13.7 million.
No, as of now, Sontheimer has not won a World Series of Poker bracelet.
He studied industrial engineering at the Karlsruhe Institute of Technology and wrote a dissertation on behavioral economics related to poker.