The Major Leagues, Arriving and Staying

Just days before the conclusion of the 2022 regular season, Stephen Vogt announced that he would retire at season’s end. By all accounts, Vogt is a popular, well-respected person and (now former) teammate. On the field, Vogt was able to carve out a solid big league career: he made two All-Star Game appearances, hit 82 home runs, and came to the plate over 2,500 times. Not bad for a 12th round pick that only picked up his first qualifying season as a 30-year-old.

To address this question, I made use of the Lahman database, which handily includes all the ingredients for an answer: player birth dates, debuts, and final appearances (as well as plenty more data). With those dates, one can pretty simply back out age at debut, retirement, and measure that space in between.

37 going on 38 at the time of his retirement, anecdotally it seemed as though Vogt embodied impressive staying power for being something of a late bloomer (despite plenty of catchers earning that late bloomer designation). Still, his career trajectory begs the question: how long do MLB careers typically last when grouped by their vastly varied starting points, i.e. debuts?

Players from the Lahman dataset have been included based on having fulfilled the following criteria: they debuted in MLB between 1990 and 2019 and they played their most recent game prior to the conclusion of the 2019 season. There is no data for retirement date, so a player’s most recent appearance having come more than three years ago is as good a proxy for “final appearance” as there is available.

But first, some context on player debuts more generally. Below are two simple histograms depicting the debut ages, rounded to nearest full years, regardless of career length.

Based on the charts above, one might say that players ascending to MLB before their 25th birthday are ahead of the curve, while those that earn that final promotion after having turned 26 are a bit late, relative to the most common debut age.

However, there are some key differences between position players and pitchers. For pitchers, there appears to be a bit more wiggle room to debut late. This could be due to any number of factors, from developmental differences for pitchers to role-specific injuries (looking at you, Tommy John). While not a single position player has reached MLB while nearing their 35th birthday in recent decades, there are a handful of such instances for pitchers.

Time in MLB can be measured any number of ways, from (1) number of games played in to (2) number of games started in to (3) the time between one’s debut and finale. Here, total games and debut to finale (in years) have been measured. Again, pitchers and position players have been split. With Stephen Vogt in mind, position players come first.

Lo and behold: earlier debuts correspond to longer careers among position players. This makes sense: players who make their debuts earlier likely did so due in a large part to their considerable talent, relative even to other aspiring professionals. Additionally, an earlier debut leaves more runway to play in MLB before retirement rears its head, as it does for everyone.

Data is well dispersed, but a clear downward trend exists nonetheless. While Stephen Vogt isn’t featured in this data given that he played beyond 2019, one may estimate where he would roughly sit having debuted at nearly 27 and a half (157 days to be exact) and retiring having appeared in ten seasons; based on this view, he indeed outperformed the majority of his peers whom debuted at similar ages.

The scatterplot changes meaningfully, though, upon adjusting the definition of “career length” to number of total MLB games, featured below.

Here, player careers are concentrated much more heavily along the x-axis, suggesting that while some careers might be longer in time, they might not include the games to match. Time lost to injury or spent playing in foreign leagues or AAA is likely the culprit for the discrepancy between these overall trends.

For pitchers, the data looks similar but with distinct features.

While again downward sloping, the trendline for “time in league” is distinctly more “hockey-stick” shaped relative to that of the position players. Put another way, after a certain point (~27.5 years old at debut) the time pitchers spend in MLB between debuts and final appearances isn’t terribly related to age at debut. Clearly, some late-blooming pitchers manage to carve out healthy amounts of time in MLB.

That lack of relationship between debut age and time in league is even less clear when measuring time in league by number of appearances.

Here, there appears to be no clear relationship between debut age and career appearances after that 27-28 year old debut age.

While sometimes less visually captivating, tables can be a bit more explicit in conferring information. For that reason, the two following tables summarize the data from the prior scatterplots.

If anything, this exploration highlights that the difficulty of arriving in the Major Leagues is dwarfed even by the difficulty of staying. In many cases, a player making his Major League debut is in fact closer to the end of his playing career than the beginning, although that is perhaps a depressing way to look at things. Maybe specifically for that reason though, it is especially worth celebrating all debuts, while highlighting those careers that stretch longer than one might have projected.