I'll analyze the performance of different Affinity variants in Modern over the last 15 days.
Based on the tournament data from the last 15 days, there is only one main Affinity archetype performing in Modern with a 52.7% winrate across 34 tournament entries. The deck has maintained consistent performance with 77 wins against 69 losses.
The current Affinity build is overwhelmingly the Kappa Cannoneer version, appearing in 97.1% of Affinity decks. This variant combines the traditional artifact synergies with Thought Monitor (85.3% adoption) and Ornithopter (82.4% adoption) as core components. The Kappa Cannoneer build has effectively become the standard, with other variants like Signal Pest Affinity being virtually nonexistent (2.9% presence).
The Kappa Cannoneer version appears to be the best performing variant simply because it is the only viable version currently seeing competitive play in Modern. The 52.7% winrate indicates solid performance in the current metagame.
Sources:
Data from 17 tournaments (100% MTGO). Recent events include Modern Challenge 32 (Sept 15), Modern Showcase Challenge (Sept 14), and Modern Challenge 32 (Sept 14).
https://www.mtgo.com/decklist/modern-challenge-32-2025-09-1512814298
https://www.mtgo.com/decklist/modern-showcase-challenge-2025-09-1412814234
https://www.mtgo.com/decklist/modern-challenge-32-2025-09-1412814287