Below, are the data I used for my research presentation at the SABR National Convention at the J.W. Marriott in Washington, D.C, on July 30, 2009. This year marks the 39th SABR National and my first convention. If you would like a PDF file of my presentation, please let me know via including your email address in a comment to this post.
Best Improvement in On-Base Percentage from one season to the next:
Name Year Age Low OBP High OBP Increase (*100)
Tris Speaker 1920 32 .395 .483 88.4
Barry Bonds 2004 39 .529 .609 80.3
Joe Medwick 1944 32 .306 .386 80.0
George McQuinn 1947 37 .317 .395 78.0
Mark McGwire 1998 34 .393 .470 77.2
Luke Appling 1943 36 .342 .419 77.1
Barry Bonds 2001 36 .440 .515 75.2
Ed Yost 1959 32 .361 .435 74.6
Ted Simmons 1985 35 .269 .342 72.5
Eddie Murray 1990 34 .342 .414 71.9
C. Lansford 1989 32 .327 .398 71.1
Dixie Walker 1944 33 .363 .434 71.0
Al Simmons 1936 34 .312 .383 70.4
Bob Johnson 1944 38 .362 .431 68.7
Tilly Walker 1921 33 .321 .389 68.0
Jim Sheckard 1911 32 .366 .434 67.6
Lu Blue 1931 34 .363 .430 67.0
Nap Lajoie 1910 35 .378 .445 66.7
Barry Bonds 2002 37 .515 .582 66.6
Frank Howard 1969 32 .338 .402 63.4
Best Improvement in On-Base Percentage from new best over previous career best (Top 10):
Name Year Age Old High OBP New High OBP Increase (*100)
B. Bonds 2002 37 .515 .582 66.6
B. Bonds 2001 36 .461 .515 54.3
F. Howard 1969 32 .338 .402 43.4
D. Walker 1944 33 .396 .434 38.1
C. Lansford 1989 32 .366 .398 32.6
B. Bonds 2004 39 .582 .609 27.7
T. Walker 1921 33 .365 .389 23.3
T. Speaker 1920 32 .470 .483 13.2
J. Sheckard 1911 32 .423 .434 11.1
L. Blue 1931 34 .422 .430 7.5