Complex sentence: His biggest achievment came in 1996 after he had won the Euro and played a pivotal role in Germany's campaign, (he saved southgate's penalty kick and ensured Germany reached the final) due to these achievements he was voted goalkeeper of the year.
Split into simpler sentences: His biggest achievment came in 1996 after he had won the European Cup and played a pivotal role in Germany's campaign (he saved Gareth Southgate's penalty kick and ensured Germany reached the final). Due to these achievements he was voted goalkeeper of the year.