While the markets for free-agent outfielder Bryce Harper and free-agent infielder Manny Machado have been slow to develop, the expectation remains that each will sign one of the biggest contracts in MLB history. 

If you're a fan of one the teams in the running for Harper or Machado, you're no doubt titillated by the idea of landing him. At the same time, you may be recoiling from the idea of investing, oh, $300 million in one player, in the event that things go wrong. First, teams are so flush with cash these days and payrolls are so historically low as a percentage of revenues that there's really no such thing as a franchise-limiting contract. Second, history suggests that Harper and Machado are going to provide a great deal of on-field worth over the balance of their careers. 

Harper was taken No. 1 overall back in the 2010 draft, and Machado was selected with the third overall pick that same year. Obviously, the scouting reports were glowing back in their amateur days (otherwise they wouldn't have been taken at or near the top of a stacked draft class). As well, Harper debuted in the majors at the age of 19, and Machado was just 20 years and 34 days old when he first played in the bigs. Debuting at such young ages is itself a sign of future greatness, and that's also why they've hit the free agent market going into their age-26 campaigns. Beyond all that, Harper and Machado have both demonstrated sustained excellence at the big-league level. 

To get an idea of that latter point, we'll turn to Wins Above Replacement (WAR). WAR is by no means a perfect instrument, but it's easily the best publicly available measure of overall player value. For position players like Harper and Machado, this means hitting, base-running and fielding are taken into account. 

WAR is measured in theoretical runs and tied to a "replacement level" baseline. A replacement-level player is any player type who's cheaply and widely available to major-league teams in a pinch. Examples include some bench players, waiver claims, or minor-league veterans -- i.e., the kind of stop-gap a team can scare up in an emergency situation. By definition, these players are not good; they are in a real sense the least an MLB team can do when it comes to filling a role on the fly. When analysts say a player was "worth [X] wins," they're talking about his WAR and not, say, the number of pitching wins or game-winning RBI he racked up.

As for benchmarks, by definition a player with a WAR of 0.0 is replacement-level. A WAR of roughly 2.0 is league-average, a WAR of 5.0 is All-Star-ish, and a WAR of, say, 8.0 or higher is getting into MVP territory. On the career front, players with WARs of 60 or more are generally Hall of Fame candidates, and if you approach or exceed 100 WAR then you're one of the greatest in baseball history. 

So, circling back to the two free agents of note, here are their career WAR totals through their age-25 season of 2018:

  • Harper: 27.4 WAR
  • Machado: 33.8 WAR

Yes, Harper has been the better hitter overall, but Machado has provided more defensive value at more premium positions, which explains his edge in WAR despite having played one fewer game than Harper. 

So where does this put them in the historical terms that will inform this exercise? For a thumbnail glance, we'll take a look at the "most similar players" listings available at the most excellent Baseball-Reference. It's a comparison tool developed by Bill James that assigns points to players based on statistical accomplishments, age trends, and positional similarities. Take a given player, and the players that wind up with the highest point totals in reference to him become his most similar players. The method has some quick-and-dirty value when it comes to guessing what the shape of a player's career might look like in the end. 

So here, in order, are Harper's most similar players through age 25:

  1. Andruw Jones
  2. Ken Griffey Jr.
  3. Justin Upton
  4. Ruben Sierra
  5. Frank Robinson
  6. Mike Trout
  7. Miguel Cabrera
  8. Tony Conigliaro
  9. Jose Canseco
  10. Eddie Mathews

Consider those names to be encouraging signs for the most part. Of those 10 names, three are in the Hall of Fame (Griffey Jr., Robinson, and Mathews); two more will be one day (Trout and Cabrera); and two others probably would've been without injury and scandal, respectively (Conigliaro and Canseco). Again, that's a list of similar players that mostly bodes very well for Harper. 

Now here are Machado's most similars:

  1. Adrian Beltre
  2. Ron Santo
  3. Andruw Jones
  4. Ruben Sierra
  5. Ryan Zimmerman
  6. Bryce Harper
  7. Cal Ripken Jr.
  8. Eric Chavez
  9. Ken Griffey Jr.
  10. Cesar Cedeno

Again, encouraging stuff. Santo, Ripken, and Griffey are Hall of Famers, and Beltre -- Machado's most similar player -- will go in on the first ballot. Notably, Harper is on Machado's list, which makes sense given their similar ages at every stop and similar overall value. 

To peer a bit more deeply into this matter, let's look at all the players who have started their careers with similar excellence. Since 1900, 53 position players have racked up at least 25 WAR through their age-25 season -- ranging from Ty Cobb and Trout (56 and 54.2 WAR, respectively) to Giancarlo Stanton and Sam Crawford (25.1 WAR apiece). Of those 53 players, 32 went on to make the Hall of Fame. As for the 21 who did not or have not, Harper and Machado are two of those names, obviously, and Trout and Stanton are very much looking like future inductees. As well, Shoeless Joe Jackson is on the list, and he'd be in Cooperstown if not for the Black Sox Scandal. 

Now let's adjust the bar a bit, starting with Machado. Let's take all the players who amassed at least 25 WAR through their age-25 seasons but less than Machado's figure of 33.8 WAR through his age-25 season. In that sense we get in the aggregate an idea of Machado's floor moving forward. 

The Machado sample ranges from Barry Bonds, who racked up an unthinkable WAR of 129.5 after age 25, to Grady Sizemore, who thanks to injuries had a total WAR of just 1.6 from his age-26 season onward. Now let's look at the average bestowals of this "Machado sample" of 23 players who, by way of reminder, had at least 25 WAR through age 25 but not as much as Machado's 33.8 WAR:

Avg. seasons remaining after age 25Avg. WAR/season after age 25Avg. total WAR after age 25




(Note: Machado's sample does not include four active players on his list -- Jason Heyward, Harper, Evan Longoria, and Stanton.)

So what do we see here? The average season for a Machado-sample player after age 25 is 4.4 WAR, and that's approaching All-Star territory. Keep in mind that's the average, which means the numbers from each player's deep decline phase are baked in. Also keep in mind that this a sample of players that fell short of Machado's through-age-25 outputs. You've got an average career length that's going to extend beyond any contract Machado signs this offseason, and you've got an average of more than 50 WAR still left on the books. If Machado comes close to that the rest of the way, then he's going to wind up being an obvious Hall of Famer. 

Given that teams these days typically pay around $10 million per 1.0 WAR on the free agent market these days, Machado's going to wind up living up to any contract and then some, at least according to the history of similar players. Sure, he could run into career-draining injuries like Sizemore or stop hitting like Heyward, but they're very much outliers in the sample. 

Now let's do the same for Harper. Again, we'll include any players who totaled at least 25 WAR through age 25, but this time we'll cut it off before Harper's 27.8 WAR. This leaves us a sample of 11 players, not including still-actives Longoria and Stanton. The results for the Harper sample:

Avg. seasons remaining after age 25Avg. WAR/season after age 25Avg. total WAR after age 25




As you would expect, these results are a bit less promising than the Machado sample, which is owing the fact that Machado has been a bit more valuable than Harper to date. That said, this still bodes quite well for Harper. His group plays for another decade-plus on average, churns out 3.3 WAR per season (i.e., comfortably better than the average MLB player), and racks up roughly 35 WAR the rest of the way. If Harper hits that figure, then he's in the Hall of Fame discussion once his career is done. 

It bears repeating that is in the aggregate is a snapshot of a pessimistic possible outcome for Harper. These players, as was the case with Machado's sample, haven't been as good as Harper to date. Go back to that very plausible $10 million/WAR figure on the market, and Harper's likely going to give good return on investment, even if he winds up breaking Stanton's contract record of $325 million. Insofar as the Machado-Harper gap is concerned, a lot of it flows from Harper's poor defensive numbers in 2018 (Machado's WAR lead was a much more narrow 28.0 to 26.1 after 2017), and his struggles with the glove last season may be an aberration

Whatever the case, no, you should not be fretting that your favored team will drown in the intrepid waters of a Harper or Machado contract. Rather, you should be raising vigorous hell that your team hasn't already signed one of the greatest free agents ever to hit the market. History, if anything, suggests that you'll get more than you give when you sign a player like Harper or Machado. 

Thanks to the Baseball-Reference Play Index for making this research possible.