Theory Cards: Sports CardsFootball, NBA, NFL and baseball - rookies, vintage and record sales.https://www.theorycards.org.uk/en-gbTue, 01 Sep 2026 09:00:00 GMTeditor@theorycards.org.uk (Theory Cards)editor@theorycards.org.uk (Theory Cards)Copyright 2026 Theory Cards60https://www.theorycards.org.uk/images/theorycards-logo.pngTheory Cards: Sports Cardshttps://www.theorycards.org.uk/The Most Expensive Sports Cards Ever Soldhttps://www.theorycards.org.uk/most-expensive-sports-cards-ever-sold/https://www.theorycards.org.uk/most-expensive-sports-cards-ever-sold/A $12.6m Mantle, the legendary T206 Wagner and a $5.2m LeBron - the record sales that define sports collecting.Tue, 01 Sep 2026 09:00:00 GMTTheory CardsSports CardsRookie Cards Explained: Why the First Card Commands the Premiumhttps://www.theorycards.org.uk/rookie-cards-explained/https://www.theorycards.org.uk/rookie-cards-explained/Why a player's rookie card is almost always the one collectors chase - and how to identify a true RC.Thu, 20 Aug 2026 09:00:00 GMTTheory CardsSports Cards