Here is a breakdown of how the pro series format works.
Stage 1 = 6 Competitors. 3 Lowest scores go to Eliminator 1 stage. 3 highest scores move to stage 2.
Eliminator 1 = 3 Lowest scores from Stage 1. Winner continues to Stage 2, losers go home
Stage 2 = 4 Competitors. 2 Lowest scores go to Eliminator 2 stage. 2 highest scores skip to Stage 3.
Eliminator 2 = 2 Lowest scores from Stage 2. Winner continues to Stage 3, loser goes home.
Stage 3 = 3 Competitors. 2 Lowest scores go to Eliminator 3 stage. 1 highest score skips to Stage 4.
Eliminator 3 = 2 Competitors, Highest score goes to Stage 4, Lowest score goes home.
Stage 4 = 2 Competitors. Highest Score Wins, Lowest Score gets 2nd place.
One thing worth mentioning is that the bottom 16 have to requalify at Nationals in October to earn their pro card back next year. That means if you're knocked out in round 1 you lose your pro card.