debut ages

It's a common misconception among baseball fans that the way to get into the exclusive statistical clubs (3000 hits, 300 wins, 135 HBPs, 500 homers, etc) is to hang around the game for a long time. That obviously helps, but the first requirement is to get into the game early. Being very very good helps too, but for now, let's look at getting into the league early. Craig Biggio's entrance to the 3000 hit club made him the 4th oldest member by age at debut date, having joined the league at about 22.5 years old. Only two 3000 hit club members reached the majors after their 23rd birthday and none were as old as 24. The average age of those 27 players, as of the day they first played in the majors, is 21. The 500 homer club started even younger with an average debut age of 20.5. All 21 players in that group joined the majors before age 23. The 135 HBP club - being more of a refined art, and a thinking-man's stat - has a slightly older average debut age of 22.3 years among its 25 members, and there are 4 members of that crew who joined the league after turning 24. Dan McGann was the oldest at his debut, at slightly over 25 years.

Among the exclusive clubs on the pitching side, the 22 members of the 300 win club have an average debut age of 21.9 years, but there are 4 of them who joined the league after turning 25. The 28 pitchers with over 2500 strikeouts also averaged 21.9 years of age when the reached the majors, but only 3 of them failed to make it into the league before turning 24. The 26 pitchers who have hit 125 batters or more averaged 22 years old at their debut, but 4 of them started after turning 25, and Joe McGinnity hit 179 batters after not joining the league until he was 28.

All that goes to show, that if you're a baseball player and you haven't reached the majors by age 24, your chances of reaching one of those major baseball milestones are very small. But, you still might be able to hit Craig Biggio with a pitch. The average pitcher who has plunked Biggio reached the majors at 23.7 years old, and 39% of them turned 24 before joining the league. There are even three players who didn't join the Major Leagues until after they turned 30, but still managed to hit Biggio with a pitch. Steve Shrenk was 30 years and 7 months old when he entered the league on July 3, 1999, and he plunked Biggio on September 13, 1999 (and pitched his final game on July 16, 2000).

It's becoming more and more important for pitchers, and players in general, to find more reasonable career goals (like joining the plunked Biggio club), because among the 635 pitchers who threw last season, only about 48% of them joined the league before turning 24, and their average debut age was 24.1. For the current decade (2000-2006), the average debut age for pitchers has been 24.8 years, which is the second highest for any decade, behind only the 1940s when war played a major factor in baseball demographics. Position players are entering the league at their oldest average age since the 40s as well. It's also true that more players over 40 years old are staying in the league, and being productive longer, but time will tell whether having more 41 year olds in the league will produce more members of those exclusive clubs, in the long run, than having more 21 year olds in the league. Only two players plunked Biggio for the first time after turning 40 (Danny Darwin and David Wells).