How many minutes did the current goalkeeper for Borussia Dortmund remain unbeaten at his previous club?
2012–13 Grasshopper Club Zürich season: The 2012–13 Swiss Super League began with a 0-2 loss against FC Sion. 2012–13 Grasshopper Club Zürich season:  After this defeat the Grasshoppers remained unbeaten for twelve consecutive matches and goalkeeper Roman Bürki was able to set a new all-time record in keeping a clean sheet in Swiss football. 2012–13 Grasshopper Club Zürich season:  He remained unbeaten for 659 minutes. Roman Bürki:  Before that Bürki was part of the winning squad of Grasshopper Club Zürich that beat FC Basel 4-3 on a penalty shootout in the Swiss Cup 2013 final.
i don't know