Jon Ludvig Nilssen Hammer is a Norwegian chess Grandmaster, chess author, and television presenter. He was born on 2 June 1990 in Bergen, Norway. His biggest achievement as a chess player was winning the Norwegian Chess Championship in 2018. He has also represented Norway in several Chess Olympiads, including in 2014 where the team finished 5th.
Hammer is best known for his role as a commentator in multiple high-level chess events. He was the main host for NRK's coverage of the Chess Olympiad hosted in Norway in 2014 and World Chess Championship matches since 2013. He hosted alongside Dirk Jan ten Geuzendam and Leontxo Garcia.
Hammer has been a crucial second to Magnus Carlsen, the reigning World Chess Champion, providing him with support during the 2013 World Chess Championship. He also co-authored a book, "How Magnus Carlsen Became the Youngest Chess Grandmaster in the World" with Simen Agdestein, providing an insightful journey into Carlsen's formative years.
As a player, Hammer achieved his first Grandmaster norm in the Rilton Cup in Stockholm in 2006/2007. He played on the top board in the World Under 16 Team Championships in 2006, where they won a silver medal. To gain his International Master title, Hammer won the prestigious Glorney Cup in 2007. He attained the Grandmaster title in 2009 at the age of 18.