Complex sentence: From 1914 to 1917, the runner-up team from the KBU tournament played a semi-final game against the best team from the rest of Denmark, with the winner facing the KBU champions in the Danish championship final.
Split into simpler sentences: From 1914 to 1917, the runner-up team from the KBU tournament played a semi-final game against the best team from the rest of Denmark. The winner of that game then faced the KBU champions in the Danish championship final.