This post is in reaction to Dave Cameron’s recent pair of entries on Fangraphs, which show that the percentage of players enshrined in the baseball Hall of Fame (henceforth, HoF) has shrunk quite substantially in recent history. I liked the argument, but I thought it missed the point to some degree. The HoF isn’t about inducting the best X% of players per decade, it’s about inducting players who meet some standard of value, and also balancing their baseball achievements against their reputations (rightly or wrongly, this is very much the case).
In the following post, I’ll examine the distribution of WAR by birth year to determine how one aspect of HoF induction has changed over time. One response to Dave’s post could be summarized as follows: if the percentage of players being enshrined has declined, perhaps that is simply because fewer HoF-type players are being born per year. This argument is not as silly as it sounds on first glance: there are various reasons, related to baseball’s eligible population changing size over time, modern medicine and training, the use of relievers, and so on, which might cause fluctuations in players’ career WAR over decades.
A disclaimer is in order: for the remainder of the post, I’ll be using WAR as an approximate metric of player value. All SABRists know that WAR is an imperfect metric, but it is fair in the sense that it is consistently applied to all of the players in the sample. If you don’t like WAR, though, you’ll think the remainder of my argument is bullshit, and that’s OK with me. If you have a better suggestion than WAR, let me know.
The Trend of Mean WAR is Constant
The experiment is simple: given all of the position players born in some year (1880-1970), what is the mean WAR they produced? The data is plotted above. Clearly, there is no significant trend: mean WAR stays constant over the entire range, and a linear regression of year on WAR produces a p-value of .17. The same, incidentally, is true of max WAR per birth year, but I didn’t think it deserved a graph.
The Trend of HoF-class Players is Increasing
The above graph is not a precise answer to the question, however. It may still be possible that despite average WAR not changing, the distribution of that WAR has been altered, so that perhaps there are more mediocre-good players and fewer outstanding players. This would lead to a decrease in HoF inductions over time. To examine this, I defined a cutoff of 60 WAR as the minimum for a player to be “in the conversation” for the HoF. I then examined how many such players were born each year from 1880-1970 (same timeframe as above).
The number of Hall of Fame class players per birth year stays in roughly the same range for the whole duration I’ve examined. In point of fact, there is a slight increase towards the end of the timeframe, and a regression of year on HoF class player number is significant, surprisingly. Rephrasing: if any trend exists in the data, there were more HoF class players born recently.
The Hall is Getting Smaller
So, there’s two conclusions from this. One, the mean WAR per birth year hasn’t changed over time at all. Two, the number of roughly Hall-class players either hasn’t changed or has perhaps increased over time.
What light does this shed on the Hall voting process? Not much, but maybe some. By this I mean the following: clearly, the threshold for induction has increased in recent years. Interestingly, however, the number of players in the range necessary to be considered for induction has also increased. One finds, upon perusal of the late 60s players, a rather suspicious trend (of course). 1968, with the greatest number of Hall-class players has a few rather familiar names: Jeff Bagwell, Mike Piazza, and Sammy Sosa. These players have in common the assumed use of steroids, and I think that is the root of the Smaller Hall.
I won’t pass judgment on the BBWAA for this decision; it is what it is. What’s clear is that the Hall has become harder to achieve. If you side with the writers, that’s because people started achieving superhuman greatness via artificial means, and so it became more difficult to disentangle the “true” HoF-class players from the “artificial” HoF-class players. If you are against this line of reasoning, it is perhaps because you don’t see a real distinction to be made there.
The Hall itself is a weird, artificial construct, designed by humans to celebrate greatness in adults who play kids’ games for lots of money. It’s hard for me to say definitively “the Hall should be this way!” or that way or another way; it’s made up, so it should be the way whoever made it wanted it to be. To the extent that the Hall influences the people that society reveres, maybe it should focus on inducting players who were good people. On the other hand, to the extent that the Hall reflects greatness in baseball achievement specifically, maybe Sammy Sosa and whoever else used anabolic steroids should be there. Perhaps there’s a perfect balance between those two purposes, but that balance is not something I feel qualified to determine. It’s fortunate, then, that I’m not a member of the BBWAA and therefore not meant to determine it.