Sometimes I get bored and decide that I want to look up information to answer a question I have. We all know that in the old game, pitchers would win tons of games in a season and pitch well over 300 innings a season. They were sort of super human. What I wondered was if the claim that pitching is in such short supply these days is really in fact true. Has pitching changed that much over the years?
I took a look at the league average ERA by year and separated it into National League and American League. Here is a table that lists my findings by year. If you read it from the top down, it shows you each decade year by year and then highlights the average ERA for that decade.
When I look at this, there are a couple of things that I notice.
1. ERA spiked sharply in the 1920’s
At first, I attributed this to the great Babe Ruth and wrote it off. Then, I started thinking through it a little more. If it was just due to Ruth, then only the American League would be affected, right? So perhaps there was something else involved in the spike.
A quick check of baseball history yielded this little nugget about 1920.
The Joint Rules Committee voted to ban the use of all foreign substances (saliva, resin, talcum powder, paraffin) as well as any other alterations (shine or emery) to balls by pitchers. As a result, the American League opted to allow two pitchers from each club the option to use a spitball for one more season. The Nationals set no limitations as long as all “practicing” pitchers were identified and any other pitcher who was caught cheating would be suspended for a minimum of ten days.~ Baseball Almanac
So now you have guys that are known to live by the spitball or other baseball doctoring methods suddenly forced to adapt their style to keep up with the change in the rules. 17 players would be exempt from the rule based on a grandfather clause due to the fact that they attributed the vast majority of their success to the spitball. The most notable of the pitchers was Burleigh Grimes, who lasted until 1934 and finished his career with 270 wins and is a member of the Hall of Fame.
2. The 1930’s were a sharp incline compared to the 1920’s in the AL
The first thing I thought again was that this had to be due to not necessarily Ruth, but the Yankees in general. There was a huge increase in 1936 and I can’t, for the life of me, figure out what this spike was due to. Any ideas on your part would be much appreciated. The only thing I can think of is that there were a ton of good hitters in the AL.
3. When you factor out the spitball, the ERA’s haven’t changed much
Look at the league average ERA’s in the 2000’s and in the 1930’s. If you do, you’ll see that pitching hasn’t changed all that much, even with the addition of many new teams over the years.
1930's 2000's Diff
National League 3.96 4.34 0.38
American League 4.58 4.56 0.02
Obviously looking at one statistic is not the end all determinant for whether or not pitching has changed over the years. However, it is an interesting fact to know that the league average pitcher, when it comes to ERA has not drastically changed over the years.