This link has that data combined, which is how the graph was created. The first two date columns have the dates when they played. Column three has all dates during the regular season. For dates when they played doubleheaders, the BA after game two is shown. For dates when they did not play, the BA of the most recent game is carried forward.
Williams had the highest BA six times: 1941, 1942, 1947, 1948, 1957, 1958. Mantle and Williams would battle again the very next season. Look for a similar post on that with their roles reversed.
Ted Williams: did he sulk in his tent in 1956, too? Monday, September 26, 2011
At the end of the 1956 season the 37 year old Williams had very little to play for. The Yankees had clinched the pennant and Williams had blown his late season BA lead over the 24 year old Yankee phenom Mickey Mantle who was limping towards the triple crown, which Williams had accomplished the two most recent times. This must have galled Williams, especially since his Red Sox played the Yankees in six of the final eight games of 1956 and Williams blew his BA lead mostly against the Yankees.
Mantle must have been injured because manager Casey Stengel had Mickey PH in six of the final seven Yankee games, including two of the the last three at Yankee Stadium against Boston. When Mantle reached base as a PH Stengel would remove him for a pinch runner even though Mantle was the fastest man in MLB...
Mantle had one RBI in each of his last three games. He needed them. Al Kaline of Detroit had two RBI in each of his final two games to finish with 128, second to Mantle's 130. Mantle led by 20 in HR: 52 to Vic Wertz 32. If anything Mantle needed to play to ensure that he would lead AL in RBI in order to win his triple crown.