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# When Do 10 Runs Not Equal a Win? Baseball Databank Data Dump 2.2

I tried to start this baseball-databank data dump series for myself last season, but it didn't take. I'm hoping to have better luck this season with shorter, and, uh, "dumpier" posts. So, for your breathless perusal (drum roll please)... historical runs-per-win conversions!

As common sense would tell you (and as you might infer from a basic of baseball history combined with the plot above), the more offense-oriented the run environment, the more runs it take to lead to a "win." I won't get into all the details here, as it's done well elsewhere (for example, at the Saber Library). There are different runs-per-win estimators ranging from from simply league runs allowed per game times two to PythagenPat. For the graph above and the data below, I've used two estimators: Tom Tango's relatively simple (lgRA*1.5)+3, and Patriot's more sophisticated PythagenPat: (lgRPG^(1-z)) * 2, where z is between 0.27 and 0.29 (last season I used 0.287, but Patriot has since told me that 0.28 has been found to  "work" the best, historically). PythagenPat is considered to be the most accurate, but as you can see above, Tango's simple conversion tracks it extremely closely, with a bigger difference at in more "extreme" environments.

But is 10 runs still a win? Taking baseball as a whole, yes, as you'll see. Even if I separate the 2010 leagues, the NL (where runs are more scarce) runs-to-wins overall conversion is still closer to 10 than to 9. Let's take a look at "modern times" (1947 to the present).

Both estimators see the last season a win was closer to nine runs than 10 was 1992. However, 2010 was closest since that season, at about 9.6 runs per win according to both estimators. It wouldn't take much of a drop to put it closer to nine than 10. In any case, to get a sense for how much of a difference between 9.6 and 10 runs per win makes, take a player who is 50 runs above average offensively. In a 10 rpw environment, that's worth ive wins. In a 9.6 rpw environment, that's worth 5.2 wins. I suppose it depends on how much accuracy you're after... Enough talk, here is the table (thrilling, isn't it?):

 Season RPG TangoRPW PatRPW 2010 4.4284 9.64255 9.617611029 2009 4.6629 9.99428 9.981617827 2008 4.6881 10.03215 10.02049645 2007 4.8335 10.25025 10.24330591 2006 4.9099 10.3648 10.35957058 2005 4.6476 9.97134 9.958039724 2004 4.8482 10.27234 10.26576675 2003 4.7722 10.15826 10.14955663 2002 4.6609 9.99133 9.978588219 2001 4.8234 10.23506 10.22784829 2000 5.197 10.79544 10.79222813 1999 5.1426 10.71391 10.71084462 1998 4.8213 10.23202 10.22475288 1997 4.8064 10.20958 10.20190305 1996 5.0661 10.59908 10.59579697 1995 4.8842 10.32624 10.32048931 1994 4.9593 10.43894 10.43455099 1993 4.6356 9.95346 9.939643803 1992 4.1256 9.18836 9.139453187 1991 4.3194 9.47913 9.446649243 1990 4.2933 9.43991 9.405442001 1989 4.1534 9.23008 9.183776802 1988 4.1526 9.22895 9.182576395 1987 4.7624 10.14366 10.13464762 1986 4.4302 9.64531 9.620479487 1985 4.3534 9.53013 9.500131794 1984 4.2777 9.41654 9.380856641 1983 4.3328 9.49926 9.467772054 1982 4.303 9.45448 9.420763484 1981 3.9977 8.99659 8.934643423 1980 4.2914 9.43706 9.402442737 1979 4.4937 9.74057 9.719583169 1978 4.1406 9.21091 9.163423382 1977 4.4841 9.72621 9.704666477 1976 3.9921 8.9882 8.925640812 1975 4.2234 9.33517 9.295055739 1974 4.1329 9.19939 9.151176325 1973 4.2256 9.33843 9.298496753 1972 3.6877 8.53151 8.430114661 1971 3.9019 8.85283 8.779901481 1970 4.3582 9.53726 9.507593059 1969 4.0885 9.13273 9.080224319 1968 3.42 8.12998 7.98489122 1967 3.7654 8.64806 8.557632809 1966 3.9974 8.99607 8.934087117 1965 3.9926 8.98893 8.926421947 1964 4.0536 9.08044 9.024420389 1963 3.9519 8.92778 8.86070202 1962 4.4871 9.73068 9.70931397 1961 4.5761 9.86421 9.847615261 1960 4.3226 9.48389 9.451649614 1959 4.4197 9.62956 9.604061418 1958 4.3176 9.47642 9.443812655 1957 4.284 9.42606 9.390875979 1956 4.4933 9.73992 9.718900369 1955 4.526 9.78895 9.769753577 1954 4.4039 9.60581 9.579272037 1953 4.6675 10.00123 9.988749833 1952 4.1944 9.29161 9.24899382 1951 4.5664 9.84959 9.832512944 1950 4.9205 10.38078 10.37575626 1949 4.6644 9.99666 9.984058775 1948 4.642 9.96298 9.949431313 1947 4.4217 9.63262 9.607252457 1946 4.0455 9.06829 9.011436281 1945 4.2057 9.30856 9.266920677 1944 4.1788 9.26817 9.224167423 1943 3.8844 8.82661 8.751553706 1942 4.0982 9.14732 9.095777231 1941 4.5277 9.79156 9.772458909 1940 4.7221 10.08314 10.07275964 1939 4.8946 10.34193 10.33640145 1938 4.9724 10.45861 10.45440785 1937 4.9582 10.4373 10.43290055 1936 5.2509 10.87634 10.87275745 1935 4.9479 10.42191 10.41735229 1934 4.9715 10.4573 10.45309002 1933 4.5127 9.76901 9.749085092 1932 4.9238 10.38566 10.38068666 1931 4.8674 10.30107 10.29495503 1930 5.6354 11.45309 11.4402923 1929 5.2526 10.87884 10.87524025 1928 4.7485 10.12274 10.11327367 1927 4.8024 10.20356 10.19576453 1926 4.7034 10.05516 10.04409445 1925 5.1894 10.78404 10.78086417 1924 4.7937 10.19057 10.18252189 1923 4.8389 10.2584 10.25159603 1922 4.9042 10.35625 10.35091208 1921 4.8766 10.31489 10.30897333 1920 4.3535 9.53018 9.500190213 1919 3.8842 8.82628 8.751197837 1918 3.6111 8.41664 8.303691707 1917 3.577 8.36553 8.247201123 1916 3.5522 8.32832 8.205985691 1915 3.839 8.75846 8.67773386 1914 3.9001 8.85017 8.777028191 1913 4.0691 9.10366 9.049217854 1912 4.5802 9.87032 9.853922514 1911 4.5523 9.82839 9.810588717 1910 3.8585 8.78778 8.709530656 1909 3.5682 8.35223 8.23248619 1908 3.3991 8.09865 7.949753065 1907 3.5945 8.39175 8.276208905 1906 3.6832 8.52476 8.422707096 1905 3.9483 8.9225 8.855020902 1904 3.8072 8.71085 8.626015118 1903 4.5396 9.80945 9.790987214 1902 4.5168 9.77514 9.755439462 1901 5.0976 10.64642 10.64328835 1900 5.3851 11.07767 11.07214784 1899 5.4791 11.21859 11.21088496 1898 5.1497 10.72448 10.72140392 1897 6.1339 12.20081 12.16019681 1896 6.2487 12.37309 12.32371431 1895 6.8593 13.28892 13.17929756 1894 7.6555 14.48323 14.26369485 1893 6.696 13.04394 12.95259388 1892 5.2458 10.86867 10.86512532 1891 5.8506 11.77591 11.75320437 1890 6.1883 12.28251 12.23784665 1889 6.1458 12.21868 12.17719232 1888 4.9631 10.44468 10.44035115 1887 6.5734 12.86007 12.78143191 1886 5.6707 11.50599 11.49179173 1885 5.3197 10.9796 10.97519937 1884 5.568 11.35201 11.34162992 1883 5.857 11.78552 11.76247384 1882 5.4041 11.10612 11.10020934 1881 5.1499 10.72481 10.7217299 1880 4.7616 10.14245 10.13341609 1879 5.2926 10.93885 10.93481193 1878 5.1552 10.73285 10.72976579 1877 5.6649 11.49738 11.48341183 1876 5.8147 11.72211 11.7012852 1875 6.1537 12.23061 12.18854209 1874 7.4844 14.22663 14.03348219 1873 8.9883 16.48243 16.01101468 1872 9.284 16.92598 16.38854802 1871 10.636 18.954 18.07390475