Warning: There are spoilers ahead for Sunrise on the Reaping.
President Coriolanus Snow and the Capitol control the odds.
Effie is one of many The Hunger Games timeline, another familiar character is responsible for first saying the phrase that would endure for decades to come in Panem.
Dr. Gaul Coined The Hunger Games' Most Iconic Phrase During The First Quarter Quell
She Provided Commentary During The 25th Hunger Games
Before Caesar Flickerman interviews each of the 48 tributes selected for the second Quarter Quell, he provides a brief look back at the 49 prior Hunger Games. During the segment focused on the first Quarter Quell, Haymitch Abernathy thinks to himself how "a relic of a woman named Gaul" delivered commentary throughout these Games, during which she was credited with coining the phrase, "May the odds be ever in your favor."

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This is a reference to the villainous Ballad of Songbirds and Snakes character Dr. Volumnia Gaul. She was instrumental in transforming the Games into a spectacle watched by everyone in Panem, along with mentoring Snow and pushing him further down a dark path. Revealing that The Hunger Games' most iconic line originated with Dr. Gaul is one of numerous ways that Sunrise on the Reaping acts as an effective bridge between The Ballad of Songbirds and Snakes and the original Hunger Games trilogy.
Dr. Gaul Coining This Line Makes It Even More Sinister
It Further Cements Her As A Disturbing Villain
"May the odds be ever in your favor" was always a disturbing line, but it feels even more sinister knowing that Dr. Gaul is the one who created it. She is the woman most responsible for keeping the Games alive and ensuring they would live on for another 65 years in an even more brutal and sadistic fashion. Dr. Gaul stacked the odds against the districts and the tributes for generations to come, which makes it all the more twisted for her to say that she hopes the odds go in their favor.
24 years after Sunrise on the Reaping, Effie is still repeating Dr. Gaul's words that mock and dehumanize the tributes, which allows Gaul's evil legacy to continue after her death.
As seen by the kindness that Effie shows the District 12 tributes, she does care about them and sees them as human, which makes her delivery of the line more sincere. At the same time, Effie is brainwashed to believe that the Hunger Games serve a greater good and even tells Haymitch this after the devastating events that make him only the second-ever District 12 winner. 24 years after Sunrise on the Reaping, Effie is still repeating Dr. Gaul's words that mock and dehumanize the tributes, which allows Gaul's evil legacy to continue after her death.