Ballpark weather

Why wind direction alone is useless

A ballpark is not oriented north. Every one faces a different way, so the same wind does something different at each. A southwest wind blows out to centre at Wrigley and across the field at loanDepot park, and knowing it is “southwest at 12” tells you neither.

MLB publishes the bearing from home plate to centre field for every park. Combined with the wind direction, that resolves into the only form the fact is useful in: how much of the wind is helping a fly ball, and how much is holding it up.

What this does not claim

No prediction of runs, totals or outcomes. Air density and wind genuinely affect how far a ball travels — that is settled physics, and it is why Coors Field at 5,190 feet plays the way it does — but turning that into a number of runs would require assumptions we would be making up.

Retractable roofs are reported as unknown rather than guessed. MLB does not announce the decision in advance and it is often made close to first pitch, so a page claiming the roof will be open is claiming something nobody knows yet.