The Decline in Complete Game Shutouts

On the great High Heat Stats, commenter Mike D was talking about the decline in complete game shutouts. Since I'm both bored and curious about the exact nature of the slide, I used the Baseball-Reference Play Index to find both the number of CG shutouts and the number of total games played in each season going back to 1916.



The notable markers that stand out include the precipitous drop at the end of the Dead Ball era in the early 1920's and the 1968 Year of the Pitcher that saw the greatest percentage in 50 years. We fell below ten percent in 1979 and haven't seen double digits since. The last season that even had five percent of games result in a CG shutout did not include the Rockies or Marlins.

The early part of the drop can be attributed to the explosion of specialized relief pitching, and it fell even further when run-scoring soared and reduced the number of overall shutouts as well. Now there aren't half as many CG shutouts as there were even in the early 90's.

The chart with all the data is below.

	CG	Total GM	PCT
1916	233	1227	18.99%
1917	247	1225	20.16%
1918	196	1006	19.48%
1919	189	1113	16.98%
1920	183	1228	14.90%
1921	120	1226	9.79%
1922	145	1231	11.78%
1923	123	1226	10.03%
1924	137	1224	11.19%
1925	106	1224	8.66%
1926	133	1222	10.88%
1927	127	1228	10.34%
1928	132	1227	10.76%
1929	120	1221	9.83%
1930	92	1232	7.47%
1931	132	1227	10.76%
1932	118	1228	9.61%
1933	166	1216	13.65%
1934	137	1215	11.28%
1935	149	1219	12.22%
1936	118	1228	9.61%
1937	137	1225	11.18%
1938	125	1207	10.36%
1939	128	1221	10.48%
1940	138	1228	11.24%
1941	162	1231	13.16%
1942	177	1215	14.57%
1943	196	1227	15.97%
1944	177	1231	14.38%
1945	186	1218	15.27%
1946	196	1233	15.90%
1947	175	1232	14.20%
1948	141	1230	11.46%
1949	171	1232	13.88%
1950	138	1230	11.22%
1951	165	1235	13.36%
1952	179	1231	14.54%
1953	156	1229	12.69%
1954	166	1231	13.48%
1955	159	1231	12.92%
1956	127	1232	10.31%
1957	139	1230	11.30%
1958	132	1231	10.72%
1959	158	1234	12.80%
1960	140	1232	11.36%
1961	154	1423	10.82%
1962	168	1618	10.38%
1963	234	1618	14.46%
1964	221	1620	13.64%
1965	191	1619	11.80%
1966	194	1613	12.03%
1967	226	1617	13.98%
1968	279	1619	17.23%
1969	242	1943	12.45%
1970	188	1943	9.68%
1971	265	1937	13.68%
1972	295	1858	15.88%
1973	236	1942	12.15%
1974	227	1941	11.70%
1975	223	1933	11.54%
1976	261	1939	13.46%
1977	176	2103	8.37%
1978	238	2102	11.32%
1979	175	2096	8.35%
1980	189	2101	9.00%
1981	135	1389	9.72%
1982	161	2106	7.64%
1983	180	2106	8.55%
1984	151	2104	7.18%
1985	163	2101	7.76%
1986	139	2102	6.61%
1987	138	2105	6.56%
1988	181	2098	8.63%
1989	150	2103	7.13%
1990	140	2105	6.65%
1991	107	2104	5.09%
1992	146	2106	6.93%
1993	99	2268	4.37%
1994	69	1599	4.32%
1995	88	2016	4.37%
1996	84	2266	3.71%
1997	89	2266	3.93%
1998	101	2430	4.16%
1999	64	2427	2.64%
2000	72	2428	2.97%
2001	74	2428	3.05%
2002	87	2425	3.59%
2003	72	2429	2.96%
2004	69	2428	2.84%
2005	63	2430	2.59%
2006	63	2429	2.59%
2007	43	2431	1.77%
2008	54	2428	2.22%
2009	63	2430	2.59%
2010	59	2430	2.43%
2011	75	2429	3.09%
2012	69	2430	2.84%