"during the tournament" is correct and usable in written English. You can use it to refer to a particular period of time in which a tournament is occurring. For example: "The crowd cheered loudly during the tournament."
Not during the tournament.
His stock has risen during the tournament.
Holes will change par during the tournament.
"But during the tournament, the players are pretty serious".
Tells about Mr. Stephens strenous duties during the tournament.
Had he had any contact with Ronaldo during the tournament?
They've still not let a goal in during the tournament.
He was broken only twice during the tournament.
PS: We are planning a special reception with the team, during the tournament.
"Just a great time all week". Crenshaw, who finished 47th, played so well during the tournament that several younger golfers paid him tributes during the tournament.
Each player partners every other player exactly once and opposes every other player exactly twice during the tournament.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com