Okay, a few more numbers to peruse.
These cover the NL and AL from 1901-60; what's nice about this is that for those 60 years both leagues remained in constant size at 8 teams apiece. This makes it possible to not only break down home and away performance in overall terms, but also by each individual position of finish.
Below are the cumulative totals for each position of finish, with the league cumulative totals summarized at the bottom of each table. What's interesting here is that there is a definite difference between the leagues over this 60 year sample.
Definition of terms:
"W%" is the percentage of more wins at home a team had than would've been expected by its overall winning percentage. This is determined by taking the numers of wins actually achieved at home and dividing by the anticipated number of wins at home (this is determined by taking the overall winning percentage and multiplying it by the number of home games played).
For example, for 1st place NL teams, the overall winning percentage is .6367; multiplying this by the total number of home games played (3063 wins + 1528 losses = 4591 games total) yields 2923. First place NL teams actually won 3063 games at home; 3063/2923 = 1.0479, which in percentage terms equals 4.79%. Thus, first place NL teams won 4.79% more games at home than their overall winning percentage would suggest they should've won.
"Pct Diff" is simply the home winning percentage minus the away winning percentage. First place NL teams had a home winning percentage which was .0613 higher than their away winning percentage.
Code:
NATIONAL LEAGUE, 1901-1960
W L Pct H W H L H Pct A W A L A Pct W % Pct Diff
1st 5813 3317 .6367 3063 1528 .6672 2750 1789 .6059 4.79 .0613
2nd 5386 3740 .5902 2869 1702 .6277 2517 2038 .5526 6.35 .0751
3rd 5100 4003 .5603 2746 1830 .6001 2354 2173 .5200 7.11 .0801
4th 4766 4348 .5229 2606 1964 .5702 2160 2384 .4754 9.05 .0949
5th 4418 4671 .4861 2419 2124 .5325 1999 2547 .4397 9.54 .0927
6th 4030 5076 .4426 2209 2341 .4855 1821 2735 .3997 9.70 .0858
7th 3687 5390 .4062 2021 2457 .4513 1666 2933 .3623 11.11 .0891
8th 3222 5877 .3541 1806 2737 .3975 1416 3140 .3108 12.26 .0867
--------------------------------------------------------------------------------
TOTAL 36422 36422 .5000 19739 16683 .5420 16683 19739 .4580 8.39 .0839
AMERICAN LEAGUE, 1901-1960
W L Pct H W H L H Pct A W A L A Pct W % Pct Diff
1st 5814 3275 .6397 3150 1420 .6893 2664 1855 .5895 7.75 .0998
2nd 5378 3714 .5915 2914 1640 .6399 2464 2074 .5430 8.18 .0969
3rd 5078 4032 .5574 2778 1793 .6077 2300 2239 .5067 9.03 .1010
4th 4755 4326 .5236 2580 1978 .5660 2175 2348 .4809 8.10 .0852
5th 4451 4622 .4906 2424 2109 .5347 2027 2513 .4465 9.00 .0883
6th 4086 4991 .4501 2263 2259 .5004 1823 2732 .4002 11.17 .1002
7th 3689 5396 .4061 2074 2452 .4582 1615 2944 .3542 12.85 .1040
8th 3104 5999 .3410 1731 2790 .3829 1373 3209 .2997 12.29 .0832
--------------------------------------------------------------------------------
TOTAL 36355 36355 .5000 19914 16441 .5478 16441 19914 .4522 9.55 .0955
It is interesting to see a considerable difference exhibited between the two leagues, particularly in the first three positions of finish and their percentage differentials.