Tom Tango asked someone to see what players with at least a 30-point wOBA reverse platoon split in their first 2500 plate appearances did for the rest of their careers, and Sean Foreman kindly provided split data from his database.
So I hacked together a Perl script to read his data and analyze it. The script lets you tweak filters, setting a minimum reverse split over some minimum number of plate appearances versus both left and right handed pitchers. Taking Tango’s suggested criteria, I found just 7 matching players, with an aggregate 40 point negative wOBA split:
Before After
vs LHP vs RHP vs LHP vs RHP
Player years wOBA PA wOBA PA Split years wOBA PA wOBA PA Split
glanvdo01 1996-2000 0.313 710 0.346 2005 0.033 2001-2004 0.321 431 0.280 1136 -0.041
batisto01 1996-2002 0.316 872 0.351 2454 0.035 2003-2007 0.291 462 0.310 1171 0.019
bergewa01 1930-1935 0.365 538 0.407 2101 0.041 1936-1940 0.385 289 0.370 1335 -0.015
jonesad01 2006-2012 0.316 870 0.358 2246 0.043 2013-2018 0.334 1021 0.344 2851 0.010
samueju01 1983-1987 0.320 840 0.351 2036 0.030 1988-1998 0.344 1556 0.310 2232 -0.034
leeca01 1999-2003 0.329 642 0.367 2347 0.038 2004-2012 0.373 1396 0.357 4402 -0.015
jacksra01 1950-1956 0.311 599 0.359 2174 0.048 1957-1959 0.277 74 0.276 326 -0.002
Total 0.322 5071 0.362 15363 0.040 0.345 5229 0.336 13453 -0.009
Tango expected the group would be neutral, and in aggregate they showed a 9-point “normal” split in wOBA. Only two of the 7 still showed a reverse platoon split, and in both cases it was much narrower than their start of career split.
But just 7 batters making his cutoff seems a little small of a sample size. So I reran, this time allowing batters with at least a 20 point wOBA reverse split, and now I get 25 players whose aggregate split is 30 points:
Before After
vs LHP vs RHP vs LHP vs RHP
Player years wOBA PA wOBA PA Split years wOBA PA wOBA PA Split
glanvdo01 1996-2000 0.313 710 0.346 2005 0.033 2001-2004 0.321 431 0.280 1136 -0.041
casege01 1937-1945 0.313 705 0.339 2216 0.027 1946-1947 0.298 129 0.270 348 -0.028
heganji01 1941-1952 0.286 1076 0.306 2123 0.020 1953-1960 0.291 876 0.296 1146 0.005
batisto01 1996-2002 0.316 872 0.351 2454 0.035 2003-2007 0.291 462 0.310 1171 0.019
spencda01 1952-1959 0.304 662 0.326 2088 0.022 1960-1963 0.366 449 0.337 913 -0.029
perezto01 1964-1970 0.352 1071 0.377 2261 0.026 1971-1986 0.388 2358 0.334 5166 -0.054
bressed01 1956-1964 0.316 827 0.342 2378 0.026 1965-1967 0.308 294 0.294 574 -0.015
mondera01 1993-1998 0.349 719 0.376 2366 0.027 1999-2005 0.383 740 0.338 2544 -0.045
wilsopr01 1998-2003 0.343 791 0.367 2242 0.023 2004-2007 0.375 367 0.320 1036 -0.054
disarga01 1990-1997 0.275 846 0.299 2251 0.024 1998-2000 0.311 213 0.310 722 -0.001
jonesad01 2006-2012 0.316 870 0.358 2246 0.043 2013-2018 0.334 1021 0.344 2851 0.010
zimmedo01 1954-1962 0.284 566 0.305 2053 0.021 1963-1965 0.294 300 0.316 674 0.022
hemslro01 1928-1939 0.296 721 0.323 2068 0.027 1940-1947 0.322 434 0.288 1108 -0.034
cimolgi01 1956-1963 0.307 1008 0.327 2258 0.020 1964-1965 0.141 53 0.287 23 0.146
ugglada01 2006-2009 0.340 645 0.370 2053 0.030 2010-2015 0.332 760 0.333 2051 0.001
suzukku01 2007-2012 0.292 780 0.321 2171 0.029 2013-2018 0.343 640 0.309 1728 -0.034
samueju01 1983-1987 0.320 840 0.351 2036 0.030 1988-1998 0.344 1556 0.310 2232 -0.034
fiskca01 1969-1977 0.358 778 0.380 2047 0.021 1978-1993 0.349 2292 0.341 4736 -0.008
jacksra01 1950-1956 0.311 599 0.359 2174 0.048 1957-1959 0.277 74 0.276 326 -0.002
bergewa01 1930-1935 0.365 538 0.407 2101 0.041 1936-1940 0.385 289 0.370 1335 -0.015
ludwiry01 2002-2011 0.328 947 0.356 2027 0.027 2012-2014 0.376 267 0.323 745 -0.053
boonebo01 1972-1978 0.301 820 0.325 2090 0.024 1979-1990 0.293 1629 0.295 3609 0.001
hollima01 2004-2008 0.388 660 0.415 2308 0.027 2009-2018 0.391 1309 0.373 3704 -0.018
hornebo01 1978-1983 0.365 638 0.389 2078 0.024 1984-1988 0.392 479 0.347 1018 -0.045
leeca01 1999-2003 0.329 642 0.367 2347 0.038 2004-2012 0.373 1396 0.357 4402 -0.015
Total 0.321 19331 0.352 54441 0.030 0.347 18818 0.331 45298 -0.017
Now we finally find a player, Don Zimmer (yes, the former Red Sox manager and Yankees coach!) who showed a greater reverse split over the rest of his career than the start, but again just barely, increasing to 22 points from 21. Just 6 other players showed any reverse split at all over the rest of their careers, and two just by a single wOBA point.
When I set the filter back at 30 wOBA points, but require fewer PA (250 against LHP, and 1000 against RHP), I find a total of 57 players, with this aggregate:
Total 0.308 25543 0.348 67831 0.040 0.349 37399 0.331 93823 -0.018
Interestingly, this group in aggregate shows an 18-point normal platoon split over the rest of their careers, after a 40 point reverse split from the start of their careers.
So overall, it seems that even players who show a pronounced reverse platoon split tend to show a more normal platoon split over the rest of their careers.
If you want to tinker with different filters, you can download the raw data Sean Foreman made available, and pass it to my Perl script with different arguments.