Jason Heyward is Perfect for the Yankees. Here's How He Breaks the 'Zombie Roster' Problem.

Typically for Brian Cashman's front office, we have not heard much about the Yankees plans for this offseason, other than that they are trying to shop Brett Gardner. As far as I can tell, the Yankees have not been directly connected to Heyward, although some have noted how well hit fits on the team. Let's review the case for Jason Heyward, quickly:

Heyward has produced 6.5, 3.4 (5.3 over 150 games), 5.2 and 6.0 fWAR over the past four seasons. He has been a remarkably consistent offensive player, with wRC+s of 121, 120, 110, and 121 over that time period. He was the 7th best hitter in baseball by fWAR over that time period, just ahead of Robinson Cano and Paul Goldschmidt. Among outfielders, only Mike Trout and Andrew McCutcheon were better.

Heyward's performance is somewhat controversial given that a great deal of his production relies on defense. He has averaged 18.3 UZR/150 over his career. In terms of defensive fWAR, Heyward is 5th in baseball over the last four years behind Lorenzo Cain, JJ Hardy Yadier Molina, and Andrelton Simmons with 58.9 runs saved.

How Heyward Breaks the 'Zombie Team' Problem

Heyward is the youngest elite free agent to actually hit the market in a long time. He won't turn 27 until August of next season. A ten-year contract will take him only through his age-35 season. I tried searching for the last MLB free agent to be this good and this young, and I couldn't find anyone in recent memory.

Here's what an aging curve for a player like Heyward looks like, via BTBS:


Most elite free agents hit the market around the age 29-31 marks. At that point, the average elite player's decline has already started, and is about to get very steep. We've seen that with players like Robinson Cano (free agent at 31) and Jacoby Ellsbury (free agent at 30), who hit the steep part of their declines almost instantly after signing the big contract.

With Heyward, on the other hand, the Yankees can buy peak years on the free agent market. Assuming they give him a 10-year deal, they'll only have to deal with a few years of steep decline. Heyward isn't as good as Cano or Ellsbury were at their peaks, but he's probably going to be better over the life of his free agent contract than either of them will be.

This is exactly the type of player that the Yankees should be dumping their money into. The Yankees biggest problem in roster construction is the zombie contract problem. I've written before about the resource curse in professional sports.

Here's the problem: almost all teams built on expensive free agent will settle into an equilibrium that looks a lot like the 2013-2015 Yankees. Free agents will be very good for a few years, but inevitably settle into a decline phase. Teams then go out and buy more free agents to compensate. If the second generation of free agents declines before the first generation's contracts are up, the team can't break out of the trap of a roster that's good enough to compete but not good enough to win championships, forever. It's a zombie team.

Here's one example. Let's create a theoretical formal model, assuming the following:

  • A team has a budget for 9 free agents
  • Free agents can either be 'elite' or 'declining'
  • An elite player is worth 2 wins above average. A declining player is MLB average.
  • All free agents are elite for 3 years, and declining for 5 years
  • All free agent contracts are for 8 years
  • The remaining roster is filled with average players (81 wins per 25 players), from the farm system or lesser free agent acquisitions.

If a team signs 1 elite free agent per year, you get a curve that looks like this:


That doesn't look good. This is a zombie team. The majority of it's elite players are always in decline over the long term. It will occasionally be good, and may occasionally sneak into the playoffs, but will never be great.

How can we fix this problem? Let's go with Cashman's apparent strategy: sign elite free agents in waves of 3. Think Burnett/Teixeira/Sabathia, or Ellsbury/Tanaka/McCann. Here's what a 3-wave curve looks like:

That's a little bit of an improvement, but still not great. The zombie team is mediocre for 7/8 seasons, and elite for 1/8 seasons.

Now, let's consider a Heyward-type free agent. Let's assume that Heyward's 8-year contract buys 5 years of elite production and 3 years of decline production. Let's also assume that you can sign two Heyward-types for every nine elite free agents. You get this:


We still get an eight-year cycle for truly great teams, but we also get a number of division-winner type years.** The pattern settles into this: 93-87-87-87-89-87-89-93-87...

Now, this is obviously just a thought experiment. We could probably substitute in real data for the parameters we asserted, and I may do that in a future post if I have the time. But I think this makes the argument very well. Teams like the Yankees desperately need to sign younger players, even if they are very expensive. Heyward is a uniquely young player in recent free agent history. They should pay the premium to sign him, instead of paying that same premium on another Cano or Ellsbury a year or two down the line.

* A five/four-wave, curve, for reference. I'm skeptical that 5 elite free agents are regularly available, so I didn't include it as a possibility. If it were possible, though, it would be a great strategy.

** There is random chance associated with any MLB season. That's why projection systems tend to underestimate the win of the best teams and underestimate the wins of top teams. For example, here are PECOTA's 2015 projections.