In game 5, Willie Ryan made what was reported to be a colossal blunder, perhaps the worst of his career, and in the end it cost him the championship in this closely contested match (it ended 4 wins each with 42 draws, but Willie was the challenger and so failed to gain the crown).
In corresponding with skilled analyst Brian Hinkle, we challenged him with the position at which Ryan blundered. Brian of course figured out the correct move in only about five minutes, but then looked further. He did some detailed computer analysis which appears to show that Ryan's "blunder" actually could have garnered a draw, but he made a real slip some half-dozen moves later, costing him the game!
Could this have all gone undetected for 55 years? Have a look at the web page that we've put together, with computer analysis, diagrams, and the complete game and notes from the book: