While there's always been a balance of top tier decks in Modern, the recent metagame has continued to shift and twist, testing into new directions and improvements to older decks.
The Day 2 metagame at Grand Prix Pittsburgh was no different:
| Archetype | Total | % Field |
| Affinity | 32 | 10.40% |
| Jund | 27 | 8.80% |
| Blue-Red Twin | 23 | 7.50% |
| Naya Zoo | 20 | 6.50% |
| Abzan | 18 | 5.90% |
| Amulet Bloom | 17 | 5.50% |
| Red-Green Tron | 17 | 5.50% |
| Infect | 11 | 3.60% |
| Merfolk | 10 | 3.30% |
| Grixis Control | 9 | 2.90% |
| Grixis Twin | 9 | 2.90% |
| Naya Company | 9 | 2.90% |
| Naya Burn | 8 | 2.60% |
| Living End | 7 | 2.30% |
| Bring to Light Scapeshift | 6 | 2.00% |
| Ad Nauseam | 5 | 1.60% |
| Goryo's Vengeance | 5 | 1.60% |
| Jeskai | 5 | 1.60% |
| White-Black Tokens | 5 | 1.60% |
| Abzan Company | 4 | 1.30% |
| Elves | 4 | 1.30% |
| Four-Color Company | 4 | 1.30% |
| Red-Green Aggro | 4 | 1.30% |
| Boros Burn | 3 | 1.00% |
| Jeskai Twin | 3 | 1.00% |
| Lantern Control | 3 | 1.00% |
| Bant Coralhelm | 2 | 0.70% |
| Green-White Aggro | 2 | 0.70% |
| Grixis Delver | 2 | 0.70% |
| Grixis Pyromancer | 2 | 0.70% |
| Hexproof Auras | 2 | 0.70% |
| Mono-Green Tron | 2 | 0.70% |
| Storm | 2 | 0.70% |
| Temur Twin | 2 | 0.70% |
| Titan Scapeshift | 2 | 0.70% |
| White-Blue Control | 2 | 0.70% |
| White-Blue Extra Turns | 2 | 0.70% |
| 8-Rack | 1 | 0.30% |
| Big Zoo | 1 | 0.30% |
| Blood Dragon | 1 | 0.30% |
| Blue-Black Faeries | 1 | 0.30% |
| Coralhelm Company | 1 | 0.30% |
| Death's Shadow Zoo | 1 | 0.30% |
| Four-Color Zoo | 1 | 0.30% |
| Green-White Tron | 1 | 0.30% |
| Hulk Combo | 1 | 0.30% |
| Jeskai Control | 1 | 0.30% |
| Mardu Burn | 1 | 0.30% |
| Martyr Proclamation | 1 | 0.30% |
| Mono-Blue Delver | 1 | 0.30% |
| Scapeshift | 1 | 0.30% |
| Silvers | 1 | 0.30% |
| Sultai Control | 1 | 0.30% |
| White-Blue Aggro | 1 | 0.30% |
| TOTAL | 307 | 100.00% |
Like Legacy and other Eternal formats, Modern is home to plenty of interesting and esoteric decks that players bring with them. Rolling things up makes the broader sections of the metagame clearer:
| Archetype | Total | % Field |
| Twin (All Types) | 37 | 12.1% |
| Affinity | 32 | 10.4% |
| Jund | 27 | 8.8% |
| Zoo (All Types) | 23 | 7.5% |
| Tron (All Types) | 20 | 6.5% |
| Abzan | 18 | 5.9% |
| Company (All Decks) | 18 | 5.9% |
| Amulet Bloom | 17 | 5.5% |
| Burn (All Types) | 12 | 3.9% |
| Infect | 11 | 3.6% |
| Merfolk | 10 | 3.3% |
| Grixis Control | 9 | 2.9% |
| Scapeshift (All Types) | 9 | 2.9% |
| Living End | 7 | 2.3% |
| All Other | 57 | 18.6% |
| TOTAL | 307 | 100.0% |
Here the story is closer to most Modern events that have preceded Pittsburgh: Splinter Twin-based decks and Affinity, followed by Jund, take the top slots and double digit pieces of the metagame. While they are longtime decks that continue to form a baseline of power for the format, small shifts do change their configurations. This weekend, classic Blue-Red Twin was the choice over Tasigur, the Golden Fang and Kolaghan's Command-packed Grixis Twin varieties, and the builds of Jund were varied collections of one- and two-ofs based on what the individual player expected to see.
The return of Zoo has been a recurring story at Modern Grand Prix, thanks to the various Commands added with Dragon's of Tarkir. Atarka's Command, alongside Wild Nacatl and sometimes Become Immense, shifted Boros Burn into a distinctly more creature-based strategy while Dromoka's Command helped buff the Voice of Resurgence-Loxodon Smiter-Lightning Bolt creature approachs. The two versions of the decks play out differently, but all Zoo decks plan to hit hard with efficient, early creatures backed up with great tricks and burn.
Collected Company has proven itself to be a useful value engine in Modern as well, appearing in some Zoo-like creature builds as well as part of the Chord of Calling solution for Abzan descendants of the old Birthing Pod decks. Similar to the variety of Zoo builds, Company decks feature a range of creatures but it's always included to dig down to whatever creatures are needed in a hurry.
One of the surprising-but-not-so-surprising surges is with Amulet Bloom, the Amulet of Vigor meets Summer Bloom deck that's taken off since its spotlight moment at Pro Tour Fate Reforged. Many of the top pros and teams have taken the deck seriously, including tenth-ranked Alexander Hayne that used it to great effect at earlier Modern Grand Prix this year.
The remainder of the major decks round out usual suspects like Merfolk, Infect and other potent combos that have become features of the smaller numbers. Whether this is one of their weekends to break through or not is an entirely different tale to unfold.