Highest at one time career batting avgs

As promised, pased on cumulativr records from Baseball-reference:

(This is actually only good for those with final career avgs of .320 or higher--it's possible some who finished below that would make the list).

Minimum 3000 plate appearances:

1. .385 Willie Keeler (1147 for 2981), ended up .341 (2932 for 8591)
2. .373 Ty Cobb (3264 for 8762), ended up .366 (4189 for 11434)
3. .365 Joe Jackson (986 for 2700), ended up .356 (1772 for 4981)
4. .364 Nap Lajoie (1086 for 2987), ended up .338 (3242 for 9589)
5. .363 Rogers Hornsby (2705 for 7454), ended up .358 (2930 for 8173)
6. .363 Al Simmons (1580 for 4349), ended up .334 (2927 for 8759)
7. .361 George Sisler (1498 for 4155), ended up .340 (2812 for 8267)
8. .361 Lefty O’Doul (974 for 2699), ended up .349 (1140 for 3659)
9. .359 Jesse Burkett (2227 for 6205), ended up .338 (2850 for 8421)
10..359 Chuck Klein (1209 for 3367), ended up .320 (2076 for 6486)
11..359 Paul Waner (1057 for 2946), ended up .333 (3152 for 9459)
12..356 Wade Boggs (1392 for 3913), ended up .328 (3010 for 9180)
13..355 Cap Anson (1163 for 3275), ended up .333 (3418 for 10277)
14..354 Pete Browning (1053 for 2971), ended up .341 (1646 for 4820)
15..354 Ted Williams (1294 for 3655), ended up .344 (2654 for 7706)
16..351 Billy Hamilton (1793 for 5103), ended up .344 (2158 for 6268)
17..351 Babe Ruth (1251 for 3564), ended up .342 (2873 for 8398)
18..350 Tris Speaker (3128 for 8942), ended up .345 (3514 for 10195)
19..348 Stan Musial (1225 for 3521), ended up .331 (3630 for 10972)
20..347 Dan Brouthers (1048 for 3020), ended up .342 (2296 for 6711)

Some of the big movers up on this list from the final career average list:

Wee Willie Keeler (I was surprised anyone passed Cobb), Chuck Klein (benefited from the live ball of the years around 1930 early in his career), and Wade Boggs (was far higher than Carew or Gwynn at one point before fading later in his career).