"The Wronski Feint is a dangerous Quidditch diversionary tactic performed by a Seeker. It is named after the Polish Seeker Josef Wronski."
From the Story
Discovered in Book 4, Chapter 8, The Quidditch World Cup
"When performing the Wronski Feint, the Seeker flies very fast towards the ground, supposedly diving towards the Snitch. At the very last second, just before hitting the pitch, the Seeker pulls out of the dive and spirals off into the air. If the opposing Seeker has been following very fast and close behind, they won't be able to pull out of the dive on time, and will usually crash into the ground.
Viktor Krum uses the Wronski Feint to distract Aidan Lynch, the Irish Seeker, during the Quidditch match between Ireland and Bulgaria."