The women's playoff for the title (won in an upset by Anna Hahn just moments ago) was almost as exciting as the press center was the night before round nine. The original round nine pairings had women's leader Jennifer Shahade playing against second-place Irina Krush! This was a legal but "slightly irregular" pairing according to arbiter Jonathan Berry. Of course it was the most exciting possible match-up, so they decided to use that set of pairings.
Soon after the pairings were released, late into the night, an agitated Jennifer Shahade called the press center to question the validity of the pairing. After she had a long talk with arbiter Carol Jarecki the pairings were changed to their "most correct" iteration. So instead of black against Krush, Shahade had black against the higher-rated Ben Finegold. But now Krush also had black, against Perelshteyn. All the players affected were quickly called and notified.
This event highlights something I learned this week here in Seattle. Swiss-system pairings are an art form masquerading as a science. Despite the use of computer programs there are still often several answers to what you would think is a simple question: who plays who? In most rounds there are several sets of pairings that are legal; nothing is handed down from the mountain on stone tablets.
Jen Shahade went on to lose to Finegold and then lose in the playoff. It's easy in hindsight to say she should have taken a game with draw odds against a weaker opponent by playing Krush. I wonder more about why she (or the arbiters!) had any influence on what should be a completely objective process. I think the arbiters did the right thing in the end under difficult circumstances, but it is curious nonetheless.
