Lukas Klein has shown strong performances in recent tournaments, proving that he can compete with players at a higher level.

Klein is known for his endurance, which can benefit him in longer matches, especially against a player like Halys, who may be more prone to stamina issues.

Klein has achieved good results in previous encounters against similar opponents, giving him additional confidence for this match.

The current playing conditions in Gstaad could benefit Klein, particularly due to his adaptability to different surfaces and altitudes.

Hanfmann has shown strong performances on the ATP Tour in recent months, demonstrating his skills on various surfaces. He has achieved some notable victories and has been able to contest close matches against high-caliber opponents.

Felix Auger-Aliassime has struggled with some injury issues in the past, and even though he has recovered, this could affect his performance and consistency in matches, especially in a close match against a player like Hanfmann.

Hanfmann is known for his strong serve and net play combination, which helps him to hold many of his service games. This ability makes it difficult for opponents to dominate him and create larger point gaps.

The conditions in Gstaad could also play a role. The altitude and surface often favour players who serve well and can play with variation. Hanfmann has proven he can be successful in these conditions, which could give him an advantage over Auger-Aliassime.