Maybe it was a wrist injury, those have a tendency to linger and sap power. Maybe he came back to soon and just had to fight through it while healing. Or, instead of speculating, I should have just googled it:

During spring training in 1925, Ruth fell ill, and returned to New York for what was reported as stomach surgery. Ruth’s ailment was dubbed “the bellyache heard round the world,” when one writer wrote that Ruth’s illness was caused by binging on hot dogs and soda pop before a game. This was nothing new, as the gluttonous Ruth frequently binged on food before games. Venereal disease and alcohol poisoning (caused by tainted liquor, a major health problem during the Prohibition) have also been speculated to be the causes of his illness. However, the exact nature of his ailment has never been confirmed and remains a mystery. Playing just 98 games, Ruth had what would be his worst season as a Yankee as he finished the season with a .290 average and 25 home runs. The Yankees team finished next to last in the American League with a 69-85 mark. It would be 40 years before a Yankees team would again experience such a poor season.

1925: In Spring Training, Ruth fell victim to his own indulgences of eating and drinking. He was diagnosed with an intestinal abscess. Ruth missed much of the season with stomach surgery and serving out a fine from New York manager Miller Huggins for insubordination. Ruth only appeared in 98 games and the Yankees finished the season at 69-85. Ruth hit .290 that season with 25 home runs and 66 RBI.

From here and here.

Does he get bonus point for trying to play GM, too?

First column = number of season
second column = first player’s WAR
third column = second player’s WAR
etc.

Don’t repeat the season numbers. Graph type is XY Scatter with connecting lines, not the line type.

players go in first row. Rest is easy to figure out.

Hence 2 * HoF.

If he were HoF^2, then his WAR would be (HoF-Replacement)^2, which, based on the graph, would be 84^2, or 7056 WAR.