On October 24, 1944, during the battle of Leyte Gulf, the Japanese Center force under Admiral Takeo Kurita attempted to force their way through the San Bernardino strait, to interfere with the ongoing American landings on the island of Leyte. The center force had already been harried by American submarines on the previous day, losing the heavy cruisers Maya and Atago (Kurita's flagship), and forcing the cruiser Takao to retire to Singapore. On the 24th, the Japanese came under relativly light yet persistent attacks from American aircraft, which crippled the crusier Myoko and eventually sank the battleship Musashi. Kurita withdrew temporarily to escape these attacks.
Later that day, Kurita returned, and sortied through the San Bernardino strait unopposed. There, they encountered the American warships of Taffy 3 in the battle of Samar. There, an outmatched force of american destroyers and escort carriers managed to hold off the last great striking force of the Imperial Japanese Navy.
But this engagement, both the hopeless American position and the utter failure of the Japanese, could have been averted. Admiral William Halsey, commanding the American Third Fleet, had actually drawn up a contingency plan to prevent such a Japanese penetration. The covering force, to be designated Task Force 34, would consist of the battleships Alabama, Washington, Massachusetts, and South Dakota, along with five cruisers and Fourteen destroyers. Said force was to be covered by two carrier groups. However, Halsey led the bulk of the third fleet north after Ozawa, leaving the passage uncontested.
Now we come to our POD. What if, showing a tad bit more caution than OTL, Halsey departs after Ozawa with all available carrier forces, but leaves Lee and Task Force 34 in the San Bernardino strait? Kurita and his fleet emerged from the passage at about 3:00 am on the 25 October. So, depending on Lee's disposition, they will make contact with the Americans roughly around that time, perhaps a few hours later. The Americans may be prepared (several officers, including Lee, seem to have been aware that something was amiss), or may not (Halsey himself seems not to have been informed of the occurances in the San Bernardino strait). Kurita is probably ready for action, but may not be expecting to have to fight his way in.
The Americans bring to the table four South Dakota class battleships (South Dakota, Alabama, Washington, and Massachusetts), two heavy cruisers (Wichita, New Orleans), three light cruisers (Vincennes, Biloxi, Miami), and fourteen destroyers. The Japanese fleet consists of four battleships (Yamato, Nagato, Kongo, Haruna), six heavy cruisers (Tone, Chikuma, Haguro, Chokai, Kumano, Suzuya), a pair of light cruisers (Noshiro and Yahagi), and eleven destroyers.
So who triumphs in this, the world's last great battleship action?