No 20 Game Winners

An interesting and surprising fact about the 2006 season is that neither league had a single pitcher that won 20 games. Chien-Ming Wang of the Yankees and Johan Santana of the Twins both won 19 games. No one in the NL won over 16 games. Has it ever happened before that there were no 20 game winners in either league? Disregarding strike-shortened seasons, the short answer is no. However, there have been several occurrences in baseball history where one of the leagues has gone without a 20 game winner. These seasons are given in the table below (excluding strike-shortened seasons):

Year	League	Top Pitcher(s) in Wins	Top Wins
1931	NL	Elliott, Hallahan, Meine	19
1955	AL	Ford, Lemon, Sullivan	18
1960	AL	Estrada, Perry	18
1982	AL	Hoyt	19
1983	NL	Denny, John	19
1987	NL	Sutcliffe	18
2006	AL	Santana, Wang	19
2006	AL	Harang, Lowe, Penny, Smoltz, Webb, Zambrano	16

We can see from the table that not having a 20 game winner is pretty rare, and not having even a 17 game winner in the NL has never happened before. Was 2006 just an unlucky season for pitchers, or is this a manifestation of an overall decreasing trend in wins by starting pitchers? The graph below shows the highest number of wins by a pitcher in each league over the years. Not surprisingly, there has been a substantial decreasing trend, with a very slight reversal of that trend in the 1950-60 period.



The overall trend is similar in the following figure, which shows the average win totals of the top 25 wins by a pitcher in each league over the years. The increase in pitcher wins during the 1950s and 1960s is more dramatic when looking at average over 25 pitchers, as well as the corresponding return to the downward trend from the 1970s onwards.



I think we can expect a few more seasons without 20 game winners in the future. Thanks to David Gurian-Peck for his help with this analysis.