ERDB

Mastering the Velocity Made Good In the high-stakes world of the America's Cup, raw boat speed through the water is a deceptive metric. To win, you must execute a superior **Velocity Made Good** (VMG). Unlike simple speed, VMG measures progress directly toward the windward or leeward mark. A boat can scream at 50 knots, but if it sails too far off the wind, its VMG suffers. We focus on this performance metric because it isolates the yacht's aerodynamic and hydrodynamic capabilities from tactical errors. The data shows that even small gains in VMG median values translate into massive distance leads over a full race leg. Deciphering Frequency Distribution Plots Performance analysis relies on heavy filtering to extract truth from noise. We remove non-foiling periods, tacks, and jibes to analyze straight-line efficiency. The resulting frequency distribution plots reveal the boat's 'sweet spot.' A thick dashed line represents the median performance, while the surrounding clusters show how consistently a crew maintains peak speed. When you see a team's distribution 'blob' shifting up the page, they are demonstrating superior drag efficiency or better power management in that specific wind range. The Anatomy of a High-Performance Maneuver Winning is often decided in the 40-second window surrounding a tack or jibe. Modern analysis centers on how a boat carries speed into the eye of the wind. Luna Rossa Prada Pirelli often bears away slightly before a tack to build momentum, sacrificing short-term VMG for a faster exit. Conversely, INEOS Britannia might show higher entry speed but struggle with the 'build' on the new tack. We look for 'meters lost' during these maneuvers to decide if a tactical shift is worth the physical cost of the turn. Tactical Implications of Leeway and Wind Angles Beyond speed, we monitor **leeway**—the sideways drift of the yacht. Teams like Emirates Team New Zealand use foil flaps and cant angles to minimize this, sometimes achieving 'negative leeway' where the boat effectively crabs to windward. Understanding these nuances allows coaches to determine if a team is sailing in a gust or simply out-designing the competition through superior lift-to-drag ratios.