402 players showed up for GP Denver, quite a few more than most people were expecting. After seven rounds of Invasion-Block Constructed, 64 of them get to keep playing on Sunday.
The Grand Prix Denver metagame is one of the most diverse in the history of Magic. Only three sets of cards are legal, but they've given rise to thirty different archetypes. If you step back far enough, I guess you can summarize most of the decks as beatdown, control, or tempo, but there are many builds within each family. Blue does seem to be the most popular color, but beyond that any attempt to metagame the field seems hopeless.
Two of the undefeated players (Worlds runner-up Alex Borteh and Sammy Batarseh) are running U-B-R Control. Interestingly, both of them sport four Nightscape Familiars in the main deck. Batarseh is from Salt Lake City and, back before there was a Pro Tour, he learned to play from Mark Justice at Justice's store.
Gabe Higa also put up a perfect record with a red-green beatdown deck very similar to the ones that dominated the Swiss at Pro Tour Tokyo. Perhaps his most interesting decision was to put 4 copies of Scorching Lava into his main deck so he could deal with enemy Spectral Lynxes.
Sometime Denver resident Dave Price is also undefeated. He's running a green-blue beatdown with a healthy dose of red removal. Typically for Price, the decklist is all fours. The King of Beatdown has always believed in figuring out which cards are best, and then playing as many copies of them as possible.
The last undefeated was Chris Senhouse, running Dark Solution. Like everyone else playing Solution, he replaced the Crimson Acolytes with Spectral Lynx. His technology was to splash enough black not just to regenerate the Lynx, but also for Dromar's Charm and some sideboard cards.
Most of the pros who came to Denver had less than a week of IBC testing under their belt since Apocalypse came out. They've been playing Standard and Extended to prepare for last weekend's World Championships. Several of the biggest names attending GP Denver came up with a unique solution to this problem: they just copied a deck down from the Sideboard's coverage of Grand Prix Kobe. Four decks managed to go 9-0 during day 1 of that 1350 player tournament and two of them were aggressive red-blue-white decks, so that's what Dave Williams, Ryan Fuller, and Dan OMS decided they should run in Denver! Williams managed to post a 6-1 mark, but Fuller and Dan-O both concluded after a few rounds that the deck was awful (and both missed the cut to Day 2). Fuller wished he had stuck to his version of The Solution, while Dan said he realized that his brother was running the best deck - Dark Domain. Steve-O is currently in 9th and the deck's designer, Brian Kibler, is 13th and also 6-1. You can read more about the deck in the feature match reports involving those players.
Sunday's format is six more rounds of Swiss, followed by a cut to the Top 8.