Sabernomics FAQ

Who are you?

J.C. Bradbury

Where can I get copies of your books?

You can purchase The Baseball Economist and Hot Stove Economics at many bookstores. There are links to some stores on the right sidebar of the page.

How do you estimate the value of baseball players?

The method I use is complex and involves many steps. I explain the general theory behind marginal revenue product estimation of player worth in The Baseball Economist. I have since modified the model, which I detail in Hot Stove Economics, but the basic structure is similar. What follows is a brief explanation.

I estimate the impact of winning (via run-differential) on revenues (using Forbes’s The Business of Baseball report, various years). Then, I estimate the impact of player performance on run production (hitters) and run prevention (pitchers). These estimates are adjusted for home-park influences. I value defense based on positional importance to preventing runs and use the Plus/Minus system to adjust for defensive quality. I then convert the run-contribution estimates to dollars using the estimates of the impact of winning on revenues. Because the impact of winning on revenue is non-linear, the reported values assume that the player is added to a .500 team. Players added to teams with above (below) average records generate more (less) revenue. The estimates are also gross (not net) marginal revenue product estimates, and therefore do not account for costs such as coaching, medical care, etc.

For projecting players into the future, I assume that league revenues grow at an annual rate of nine percent, which is consistent with the history of league revenue growth. I also make an adjustment for aging based on a detailed study of how baseball players age.

Would you be willing to speak to my college/business/community group?

Absolutely! Just send me an e-mail.

Will you add a link to my site? I added a link to yours.

This is the most common request I receive. I am always happy to learn of new sites with related interests; however, it is my policy not to “blogroll” or trade links. The problem is that I either have to say yes to everyone, no to everyone, or via person e-mail write, “I don’t want to link to your site.” My policy is that I link to blogs that I like and read on a regular basis. And just because I don’t link to a site doesn’t mean I don’t read it.
UPDATE: I’ve suspended the blogroll. What’s the point really? It’s kind of an outdated concept, because there are better ways to find links on the web. If you can think of a good reason to have one, let me know

Do you like pointers?


What are your advertising rates?

Please visit the links provided on the advertising strips.

Will you help me with my school project?

I’m sorry, but I can’t do this. I don’t want to be in the position of providing help on a project that is supposed to be independent. Even if your instructor says getting help is OK, I’m not going to be interested. However, I am always happy to read completed school projects.

I posted a comment, but it hasn’t appeared.

Because of spam, I have the spam filter on really tight. Sometimes I don’t have an opportunity to moderate the comments, and sometimes legitimate comments get classified as spam by the filter. If you don’t see your message within 24 hours of posting, please feel free to send me an e-mail inquiry.

You posted a link to a study that I don’t agree with. Can I express my disagreement on your site?

Most of the time, I prefer that you not critique other studies on my site. The reason for this is that the critique should be directed to the author. If your critique relates to some comments that I have made, then you can comment on them. But, I do not want to be in the position of having to defend someone else’s work just because I link to it. Sometimes, I just want to say, “hey, this looks like a neat idea/result.” It may turn out not to be, but I want the discussion to take place after interacting with the study’s author(s). However, you may criticize my work.

Can I post an idea on your site?

I am the sole poster on this site at this time. If you have an idea or study that you want to post, I suggest starting your own blog. It’s quick, easy, and cheap. 🙂

I have a suggestion for your site. Would you like to hear it?

Suggestions, yes. Complaints, cram it.

I often find spelling and grammatical mistakes in your posts. Why don’t you be more careful?

Yeah, I hate this too. I notice it all the time. Unfortunately, it’s something I’ve decided to live with. I like blogging because it is a good way to post my thoughts quickly and informally. If I proofread my posts as much as I wanted to, I wouldn’t post nearly as often. As George Stigler once said, “If you never miss a plane, you’re spending too much time at the airport.”

I don’t like reading about X. I want you to write more about Y or I’m going to quit reading.

You’re an idiot! Your posts are ridiculous and nothing you say is worth anything.

Comments like these—yes, I really do get them occasionally—are annoying. Please, think about what you’re writing before you send something like this. I blog because it’s fun. That’s what blogs are for. When I get e-mails or comments like this I immediately delete them.