The Best Roster Cores: 2014 End-of-Season Edition

It’s hot stove time, when we shift our focus from the season that was to the season on the horizon. Tires are kicked, trades are proposed, and free agents are considered. During it all, metrics like WARP allow us to summarize the performance of individual players. But what about the overall core of a team’s major-league roster? How can we say, objectively, whether a team has built a core of ongoing contributors? Or, by contrast, whether it has been overly reliant on transient (e.g., departing) assets?

A productive core consists of two things: good players under long-term control, and good players who are not too old. Players under long-term control allow a team to be patient and avoid expensive, volatile solutions (except in those cases when the players under long-term control become those expensive, volatile solutions); players who are younger also tend to play more games, be more productive, and remain productive for longer.

To evaluate each team’s production from core contributors, I created a profiling system called Core Value. The system debuted at the conclusion of the 2013 season, and we used PECOTA before the 2014 season to project possible improvements. Now, with the 2014 season concluded, we can see what actual progress was made.

Methodology

The method is as follows:

1. Tabulate and combine all batting (by BWARP) and pitching (by PWARP) contributions by each player in the major leagues this year.

2. Create a Control Index by weighting the years of remaining team control covering each player. A maximum of five years of team control is credited, and the variable is centered at two years. So, for example, players under five years of team control have a Control Index of 2.5 (5/2); players in a contract year have a Control Index of .5 (1/2).

3. Create an Age Index by weighting the proximity of each player to a peak baseball age, or more precisely, the age at which we start seeing serious and continued decline. As with the previous studies, I’ve used a peak age of 27 for all players and positions, although there are other (very good) opinions on that issue. [1] This means that a 30-year-old player will be penalized at a rate of .9 (27/30), whereas a 22-year-old player will experience a bonus rate of 1.23 (27/22).

4. We calculate so-called core “wins” or “value” by multiplying each player’s total WARP times that player’s Age Index and Control Index. The aggregate core wins for a team is tabulated, and the original aggregate WARP is subtracted. The resulting figure, which I call Core Win Differential, reflects the extent to which the team’s contributions were provided from younger, controlled players.

5. Although roster depth is important, teams strongly benefit from having their stars also be a part of their core. For that reason, we also track so-called “core players” — stars who amass 5 or more core wins over the season. [2] We tabulate both the total number of core players on a team, as well as the number of pitchers who are core players, as good rosters tend to have both.

6. Finally, we rank each team's comparative performance, from 1 to 30, in each of these three categories, and average the three scores to come up with a final, composite rank of what we call Team Core Value.

Before we provide the results, there are two caveats. First, this system is descriptive, not predictive. We are telling you how each team did this particular year. This does not necessarily mean the team will do the same or better next year, or that there is no other path to success.

Second, for a variety of reasons—injury, distractions, bad luck, etc.—a player’s performance in a given year might not be representative of their true talent. Some players have off years, and others have fluky good years. Again, we are telling you how the players, and their teams in the aggregate, actually did; you, the reader, can decide whether you think a particular team’s performance is representative of future results or not.

Results

Here are the team rankings from 2014:

Don’t get too excited about a difference of a few spots between teams. In general, the meaningful locations are (1) the upper quartile (the top eight teams), (2) the bottom quartile (the bottom eight teams), and the remaining teams in the middle (the interquartile range). Slight changes in methodology, such as lowering the peak age by a year or two, or using WAR numbers from a different method, can move teams within brackets a bit, but the upper and lower quartiles, particularly at the extremes, tend to be fairly stable. This is encouraging and suggests some robustness to the approach.

What do we learn from this year’s rankings, particularly as compared to last year? We could talk at length about every team, but a few developments jump out:

It’s Nice to Have Lots of Money . . .
Money seems to buy fewer wins than ever, but as in real life, more money makes things easier. The Dodgers are this year’s Core Value champs, and they can largely thank their ability to trade for contracts like that of Adrian Gonzalez, extend Clayton Kershaw, sign Zack Greinke off the open market, and recruit Yasiel Puig as a young international free agent. At the same time, the Dodgers have not merely purchased their success: Scott Van Slyke was a late-blossoming draftee, Kenley Jansen was an undrafted free agent, and the Dodgers did draft Clayton Kershaw to begin with. Overall, the Dodgers have a stable core of roster assets on which to rely in 2015, provided they can agree on who gets to play each day.

But Money Does Not Guarantee Success.
One subtext of the 2013 World Series was how differently the two teams involved had been constructed: The Cardinals ranked first in our measures last year, whereas the Red Sox, thriving on production from short-term free agency moves, ranked near the bottom. The Red Sox of course triumphed, showing that a young roster core does not automatically translate to championships. Acknowledging this, we nonetheless noted the following about the Red Sox:

Their roster generated more WARP than any other club in the 2013 regular season. However, a great deal of that production is heading out the door, and the aging remnants should struggle to replace it from within. . . . Last season may have been do or die year for the Red Sox. They registered only three Core Players, and none of them was a pitcher. Of their top 10 contributors in 2013, five of them are on the open market. The Core Wins formula discounts the contributions of the departing free agents accordingly, and the Red Sox now face a predicament heading into 2014. With a top-rated farm system and substantial financial resources, they have more ability to replenish than most, but they have a lot of work ahead of them.

This assessment proved prophetic. Jacoby Ellsbury left, other players on the wrong side of 27 regressed, and the young players counted on to fill the gap—like Jackie Bradley Jr. and Xander Bogaerts — were not yet up to the task. Of course, thanks in part to that disappointment, the Red Sox now have a protected draft pick in addition to their fine farm system and deep pockets, so no one is feeling sorry for them.

By contrast, while the Red Sox floundered early and often, the Cardinals, despite injuries, similar pitching regression, and an overall slow start, managed to grind out 90 wins in a tougher division and returned to the postseason.

Good News in Cleveland
Cleveland did extremely well in these rankings last year, ranking fourth in the league for roster core quality. I didn’t comment on it at the time, as Cleveland had just enjoyed a Cinderella season and its team WARP obviously reflected that. But here we are for a second year in a row, and Cleveland not only maintained its top-quartile status, but moved up. It did so by coaxing strong performances from additional core assets for a second year in a row. Whereas last year featured superb production from Jason Kipnis and Carlos Santana, this year the club added outstanding performances from Michael Brantley and Corey Kluber (both 6+ WARP). In a fairly weak division, this emerging roster core has the needle trending up.

Worrisome News in Cincinnati
The best parts of Cincinnati’s rotation are approaching free agency, and the Reds appear to have extended the wrong starter (Homer Bailey). In the lineup, Joey Votto is under long-term control, but didn't stay healthy. Jay Bruce, despite playing 137 games, had less BWARP than two members of the starting rotation.

Two years ago, Cincinnati was the envy of the league, with a potent combination of pitching, defense, and lineup power; now, as they tumble to nearly last in these ratings, there is a sense that Cincinnati’s window is closing fast. Both Votto and Bruce should regress positively next year, but Cincinnati’s core seems to be withering before our eyes.

Top Individual Performances

We’ll conclude by listing the individuals who offered the highest core value to their teams this year. Here are the top 25:

That Mike Trout guy is the worst: He always needs to be on top of all the lists.

You’ll notice a few trends here: the most valuable core players are under control for four or more years, either through free agency contracts or the collective bargaining agreement. They also tend to generate 4 or more WARP, and usually, but not always, are on the right side of 27. Naturally, as you consider the value of these players in future seasons, you need to take account of their Control and Age Indexes accordingly.

Conclusion
Team Core Value is just one way of profiling a team’s roster. But knowing the quality of a team's core allows for more informed use of future projections and suggests the best focus for the team’s farm system, as well as the ideal uses of a team’s payroll flexibility. Certain teams have the luxury of relying largely on their current rosters, whereas others have some (comparatively risky) shopping to do.

Jonathan Judge is a product liability lawyer. You can follow him on Twitter (where he talks about baseball, not product liability) at @bachlaw.

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Appendix

Here is the list of core players by team: