MLB's Convoluted Service Time Rules Cloud Rookie Status, PPI Eligibility

Image credit: Jasson Dominguez (Photo by Rich Schultz/Getty Images)

What makes a rookie a rookie?

The word itself is younger than baseball. The Oxford English Dictionary’s first reference to a rookie comes from 1868. It appears to have jumped from describing young police recruits and soldiers to being a moniker for baseball neophytes at some point in the early 1900s.

You probably know that Jackie Robinson was MLB’s first official Rookie of the Year in 1947. The award now bears his name. But did you know that, at that time, rookie qualification was determined solely by award voters?

In the segregation-era 1940s, there was no chance that any voter was going to view Robinson’s time in the Negro American League with the Kansas City Monarchs as enough to disqualify him from rookie status. But if a voter in 1947 had said that Negro League experience removed Robinson’s rookie status, no one could have pointed to a rule one way or another.

In 1950, Cleveland’s Al Rosen led the American League with 37 home runs. He earned MVP votes, but didn’t get any Rookie of the Year votes. Voters decided his 58 at-bats over the previous three seasons were disqualifying. Red Sox first baseman Walt Dropo’s 44 at-bats the previous year, however, weren’t viewed as a problem. Dropo was ROY.

As a bonus baby, Al Kaline spent the second half of the 1953 season on the Tigers’ roster but then finished third in 1954 ROY voting.

A few years later, Kaline wouldn’t have been eligible. In 1957, rookie qualifications were finally defined. Players could have no more than 75 at-bats, 45 innings or have been on an MLB roster between May 15 and Sept. 1 of any previous season. That rule seemed too restrictive, so it was rapidly changed to 90 at-bats, 45 innings or 45 days on an MLB roster before Sept. 1.

In 1971, it was changed again, this time to 130 at-bats, 50 innings or 45 days on the roster before Sept. 1. But even with rules, there have still been issues.

A voter cast a ballot for Red Sox third baseman Frank Malzone in 1957, even though he had spent more than 45 days on the roster and had 123 at-bats over the previous two seasons.

In 2008, Reds righthander Edinson Volquez somehow finished fourth in the National League ROY voting—he received three second-place votes—even though he had made 17 starts and pitched 80 innings for the Rangers over the previous three seasons. That’s not a rookie by any logical standard, and it happened in the age of Baseball Reference.

As editor-in-chief of Baseball America, I’ve probably spent more time than I’d like thinking about this. That’s because 2024 is our 43rd year of ranking the top prospects in each organization. And like we have for the previous 42 editions of our Top 10 prospects, we will use a straightforward criteria for determining which “rookies” are prospect-eligible.

Going back to the first run of Top 10s in 1983, BA founding editor Allan Simpson determined prospect eligibility by using the following rookie playing-time standards: no more than 130 at-bats or 50 innings in a player’s MLB career.

Simpson left out the 45 days of active MLB service requirement, because, at that time, there was no way to compile it. The American and National leagues published their annual “Red Book” and “Green Book” official record books—which sometimes included lists of players with updated rookie status—but those volumes were published long after BA began reporting and writing its Top 10s.

BA has added one more piece of criteria for prospect eligibility since then: a pitcher must not exceed 30 career MLB relief appearances. We call that the Daniel Bard Rule. Bard spent five months in 2009 on Boston’s big league roster, but he threw just 49.1 innings over 49 appearances. It seemed silly to deem him a prospect.

For our 2024 prospect lists, we’ve also stopped ranking “foreign professionals,” who are defined by MLB as players who are at least 25 years old and have played as a professional in a foreign league—typically in Japan, Korea or Cuba—for a minimum of six seasons.

Call this the Yoshinobu Yamamoto Rule. He signed a $325 million contract yet remains eligible to win the NL Rookie of the Year.

That is a long preamble to explain how close we came to altering our prospect eligibility rule again for 2025.

When BA first started ranking prospects more than 40 years ago, it wasn’t possible to obtain accurate MLB service-time information in a timely manner. In the information age we live in today, we have cleared that hurdle—but still we are missing a key component.

As of yet, it is impossible to assess days of active MLB service with 100% accuracy. This is not a statistic that is actively kept. MLB makes the calculation manually.

And it’s trickier than that, because there are other rules at play. If a player is optioned to the minor leagues for fewer than 20 days, that minor league time is converted to MLB service, making it “active” service. That nearly disqualified Mike Trout from being the AL Rookie of the Year in 2012. In the end, MLB ruled Trout eligible because it decided that the spirit of the rule should win out over a technicality.

That’s not the only confounding factor. When the 2025 season begins, Yankees outfielder Jasson Dominguez will be eligible to win the AL Rookie of the Year award. However, the Yankees will not be eligible for a Prospect Promotion Incentive draft pick if he wins ROY even though Rookies of the Year who also rank as Top 100 Prospects typically garner a PPI draft pick for their teams.

Why? It might be easier for me to explain why we measure milk in gallons but soda in liters.

Dominguez spent a significant portion of the 2024 season on the major league injured list as he recovered from Tommy John surgery. While that did not add a day to his active service time, it did count as overall service time.

So, Dominguez has more than 60 days of overall MLB service time—130 days, in fact—which means he cannot pick up PPI eligibility. PPI rules state that eligible players must have fewer than 60 days of total MLB service, in addition to meeting the rookie standard of no more than 45 days of active service.

So Dominguez fits the definition of a rookie, and he’s a prospect by those same definitions. But he won’t be eligible for the Prospect Promotion Incentive.

Maybe one day that will all make sense.

Thank you to MLB historian John Thorn for his assistance on MLB rookie rules.