Pandemic Iberia: the best standalone
Catan's placement phase is the game's most analyzed and arguably most impactful decision. Initial placement determines your resource access for the entire game. A misplaced second settlement can be unrecoverable regardless of how well you play the remaining game.
The placement math is straightforward: the most likely dice results are 6, 8, 5, and 9, in that order. Settling where two or three of these numbers intersect creates reliable resource generation. Diversifying across resource types creates trading leverage. Settling all three settlements on the same number creates high variance that experienced players exploit.
For new Catan players: understand the probability distribution before your first placement. The numbers printed on each hex tell you exactly how likely that resource is per turn. Building your settlement at intersections of high-probability hexes across different resource types creates a stable foundation.