So, like many other Mets fans recently, I've been contemplating the ramifications of the Mets (hypothetically) signing Michael Bourn to a $15M contract. Some pros and cons ...

At first I was against it because he's 30 and I was under the impression that speed guys age badly because guys age 30 or older are rarely ranked towards the top of stolen base leaders. However, I found evidence compiled by Jeff Zimmerman saying that the WAR of speed guys actually retains good value post-30: http://www.beyondtheboxscore.com/2011/5/31/2199146/hitter-aging-curves. So I was thinking, "Maybe signing this guy isn't that bad an idea."

I made a full swing in favor of it after seeing that Fangraphs says he's been worth ~$22M/yr for the last four years and even in the worst of those years (2010 & 2011) he was still worth over $18M.

However, I think I've finally settled on giving a thumbs-down to the possibility because of what I call the "Buster Olney Rule." Last winter, while Olney was answering a mailbag question, I stumbled across this:

From the mailbag

Note: I wrote the other day that, generally speaking, spending 15 percent of your payroll on one player is probably something teams would shy away from.

Q: The 15% rule is a good one, Buster, but it's not enough. The real rules are: no one player more than 15%; no two more than 25%, no three more than 33%, no four more than 40% and no six more than 50%. It's how you go about constructing a roster. Greg, L.A.

A: Greg: Generally speaking, I'd bet there are a whole lot of general managers who agree with you.

So let's take a look at a hypothetical roster using math that conforms to ~$112M payroll, the average 2012 playoff payroll (via Cot's):

Now let's also take a look at a hypothetical payroll using math that stays at the $189M luxury tax threshold:

Under either scenario, that puts a $15M player as one of the top two or three best-paid players on any roster you could devise using the Olney Rule. And whether he's worth it or not, I don't believe that a player who brings so little to the table offensively deserves to be such a centerpiece of your organization. I have to imagine that an all-glove/no-hit center fielder could be had for millions less than what Bourn is asking for. Final Verdict: Please Do Not Sign Michael Bourn, Mr. Alderson.

EXCITING POST-SCRIPT: The more I thought about it, I wasn't getting on board with how the math worked on the Olney Rule so I crunched a bunch of numbers myself. Using all 2012 payrolls from Cot's, I found that the average MLB payroll of $98.1M has 63% of its payroll allotted to its six top-paid players, which would be about $13M more for those guys combined than the Olney Rule allows for. So I was right to think that the math didn't add up. I don't quite have the time to draw many concrete conclusions yet but at first glance I can still say this: all signs I see point to only having two or three guys on your payroll making $15M or more. So if Bourn's asking price is still $15M then I'm still not a fan of having him tie up a top-3 payroll spot. You can see the math I've worked out so far here: https://docs.google.com/spreadsheet/ccc?key=0ArnrUtDIk9i0dGx5YnVKa1g5QnBmRUhZZ005X2RIYVE&usp=sharing