Rulings, with receipts

Guides hedge. These don't. Each verdict is a short ruling on a decision runners agonize over, backed by course data, 10-year race-morning weather, and the same heat math our training plans run daily — plus what to do instead.

• Don't make Miami your first marathonJuly 6, 2026
  The course is flat. The dew point doesn't care.
• The Chicago lottery is not a race planJuly 6, 2026
  A first marathon needs a start line you control.
• Flat doesn't mean fast in FloridaJuly 6, 2026
  Hills cost you seconds. Dew point costs you minutes.

Every number is computed live from the catalog — see the methodology.