The following two pdf files contain the general report of Duel 2016 in Ostrava. The first file is the English version, the second file is in Czech.
The Czech TV was at the competition in Ostrava in 2016 to produce a news item, in which some participants and teachers were interviewed. The following link forwards to the news video, the item about the Duel competition begins at minute 136:30 and lasts to minute 138:40.
Official Mathematial Duel 2016 Problems and Solutions document
A report of the whole competition was written by Daniel Horiatakis, a student of BRG Kepler, in German.
A report of Sunday was written by Adrian Steinmann, a student of BRG Kepler, in German.
Johannes Trattner, a student from BRG Kepler Graz, who participated at Mathematical Duel 2016 wrote a report of Monday in German.