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Trade Poll Valuation: Matt Carpenter to Boston

St. Louis Cardinals trade poll

Judging by the number of voters, Brenden’s trade polls are a fan favorite. Here at The Intrepid STL, we’re working to make them even better. Starting now, each trade poll (or most) will be accompanied with a short post explaining the valuations of the deal for each side.

Trade valuations are complicated. In a perfectly efficient market, each trade would match surplus values exactly. Surplus value is the dollar value a player is worth on the field over the salary he’s paid. You can calculate the surplus value of a contract, of a player’s expected earnings and production through team control, and for prospects. If you’re interested in the surplus value calculation, I outline that in detail below. For now, let’s dive into this trade poll summary.

Trade poll summary

Today, we’re looking at moving everyone’s new least favorite diva, Matt Carpenter. The Cardinals are three games under .500. They’ve slid down to fourth in the NL Central standings. Next year looks like more of the same barring any major trade acquisitions or free agent signings, and we’re not optimistic any of those big moves will be made.

Carpenter’s contract includes a team option for the 2020 season at $18.5 million. Under these projections, however, he is not expected to be worth that salary. In that case, the team will decline the option and pay his $2 million buyout. Below is Carpenter’s valuation table.

St. Louis Cardinals trade pollZach Gifford | THE INTREPID STL

Next, we searched for a team with a need for a first baseman or DH. We settled on the Red Sox, who have been getting underwhelming production from Mitch Moreland. Additionally, Boston can use Carpenter at DH now or in the future. By doing so, they might limit Carpenter’s WAR decline and squeeze out more surplus value than the $21.6M shown.

So what might the Cardinals get? Rafael Devers is off the table since he projects too highly. 21-year-old third baseman Michael Chavis is an intriguing option, though. He broke into Baseball America’s Midseason Top 100 this year at #96 after posting a 184 wRC+ in 59 games in High-A. Most evaluators weren’t high on him to start the season, however, so his aggregate ranking may still only be around #125. In that case, he’d have a present surplus value of about $18 million. Using just his top 100 BA ranking,

To finish up the deal, the St. Louis Cardinals would likely acquire another of Boston’s lower top ten prospects.  Josh Ockimey stands out as a first baseman with power potential. The 21-year-old lefty is posting a 132 wRC+ in High-A ball, including 10 home runs. His present surplus value is likely about $4.5 million.

St. Louis Cardinals trade pollZach Gifford | THE INTREPID STL

So there we have it. Find the poll on Brenden’s timeline (@bschaeffer12) to vote, and let us know what you think in the comments or replies. As promised, the valuation methodology is detailed below.

Our votes

Gifford: Yes; the path forward for the Cardinals isn’t clear. Making this move adds depth and upside to the Cardinals position player prospects and gives Voit an opportunity to showcase himself full-time.

Schaeffer: No; the concept of exploring Matt Carpenter’s trade value fascinates me. Though he’s the best hitter on the team, his defensive profile has forced the Cardinals to wedge him into first base, where his bat doesn’t profile as precisely (how many first basemen hit hit leadoff?). That said, the Cardinals are a few pointed moves from contention in 2018. Moving Carpenter for prospects–albeit, talented ones–who don’t project to contribute to an NL Central run next season doesn’t quite make sense for the organization, for me.

Joe Schwarz: No.

StlCardsCards: No; I wouldn’t trade Matt Carpenter for anything but a 20-year-old female with an oral fixation.


To determine a non-prospect’s surplus value, I start with FanGraphs Depth Chart projections for the current season. I convert the player’s projected WAR to a rate-stat (600 PA for hitters, 180 IP for starting pitchers, and 50 IP for relievers), then apply estimated playing time. Estimating playing time is a key step, because even the most talented players don’t produce any value if they don’t play. Further, adjusting playing time results in a more realistic valuation for players who slip below replacement level or decline into a bench role.

To project future season WAR, I use an average aging curve. I calculated separate aging curves for hitters, starting pitchers, and relief pitchers; this way, the aging pattern and general decline matches the player’s positional peers.

The cost of WAR ($/WAR) for 2017 is set at $9.0 million, consistent with Ben Markham’s research. I then grow $/WAR at 5.5% through 2019, consistent with opening day payroll inflation. After 2019, I increase $/WAR at a 3.0% long-term growth rate.

For moves made in-season, the cost of WAR is doubled for that season, consistent with Dave Cameron’s research at FanGraphs. For example, since we  are in the 2017 season, the cost of WAR in 2017 is $18.0 million instead of $9.0 million. No adjustments were made to account for “star” players, since recent research by Matt Swartz suggests cost per win is linear with respect to player talent.

A player’s projected value in any given season equals his projected WAR multiplied by that season’s $/WAR.

Player salary data is compiled from Baseball Reference, Spotrac, and FanGraphs. For players in the team control process, future salaries are estimated as follows: renewable-eligible players receive a salary estimate of the league minimum or their previous year’s salary, whichever is higher. For arbitration eligible players, I implemented the 25/40/62 rule (or 20/33/50/70 for Super Two’s) outlined by the Point of Pittsburgh.

Nominal surplus value is calculated as the player’s projected value less his salary for each season.

Wins now are worth more than wins later, and wins later come with significant risk. Therefore, I applied an 8% annual discount rate to future WAR. This results in a present surplus value, which is summed over the length of a player’s control for a total present surplus value. This is the amount the player is worth to other teams.

To value prospects, I used the Point of Pittsburgh’s Top 100 prospect WAR estimates, $9M/WAR, and the team control salary estimates outlined above to determine a prospect surplus value. Based on recent research at FanGraphs, I discounted those values at a 20% aggregate rate. So, this way, a prospect with a $50 million nominal surplus value is assigned a $40 million present surplus value.  Next, I used the available data to estimate a value for the “top” 300 prospects. The best prospects are worth, on average, between $80 and $90 million, and the lowest prospects are worth about $4 million.

This isn’t perfect; some prospects take longer to get to the MLB than others, and this method only uses their value relative to other prospects, not their raw talent level. But, for these purposes, it gets the job done.

Finally, below are the average aging curves generated by my analysis of qualifying seasons from 2006 to 2016. The sample sizes were generally large enough from age 24 to 35; for players younger than 24 or older than 35, I took a few liberties to simplify the curve. The overall aging pattern exhibited here runs against the traditional notion that players peak in their late twenties, but the data is what it is.

St. Louis Cardinals trade pollZach Gifford | THE INTREPID STL
St. Louis Cardinals trade pollZach Gifford | THE INTREPID STL


St. Louis Cardinals trade pollZach Gifford | THE INTREPID STL

Thanks for reading!