Bill James conducts comes at the range of the peak seasons of hitters from a new angle (subscription may be required). This study confirms many other studies over the years that the peak ages for players lie in the seasonal age 25-29 years, with most likely peak at age 27.

When I was in college I had a conversation with a crew coach about the Olympics. There was a time when people who coached sports were considered professionals and were not allowed to compete in the Olympics. This made it tough for rowers to compete after college, as most people needed to work full time jobs, which left little time for training. The coach pointed out to me that rowers peaked at age 27, so at least in the US, most crew competitors did not have a chance to reach that peak competitively. That had changed by the time we had the conversation (around 1980), so that one could coach but not compete for money and still be considered an amateur.

A few years later, when I started reading the Baseball Abstracts, I was not surprised when I read that peak age in baseball was also 27. Well into the 1990s, however, I heard people in the business say that the peak age was 30. This was one thing that led to owners making a number of bad free agent signings, and it was to the advantage of the players not to knock down the myth. If peak age 30, six years to free agency makes sense. If peak age is 27, then most players will be past their primes when they get a chance to market themselves to teams. Now that front office understand when players peak, they have become masters of manipulating service time to capture peak seasons under team control. In the next CBA, the MLBPA should really concentrate on moving free agency to at most the player’s peak seasons.

One way might be five or six years of team control. That would count both major and minor league time with the organization. So an eighteen year old is drafted, plays his first full season at 19. That would be year one. He would be a free agent after his age 23 season. Drafting someone out of college at age 22 would make that person a free agent after age 27. This would encourage teams to bring up their best players to the majors as soon as possible.

I suspect it might hurt players coming out of high school. Of course, with MLB likely to contract the minor leagues, competitive independent leagues might spring up with local, young stars, similar to the industrial leagues of the early part of the twentieth century.