Fantasy: The Impact Of New September Roster Rules

Image credit: Nico Hoerner (Photo by Nuccio DiNuzzo)

Now you see them. Next year you won’t.

Earlier this year, Major League Baseball and the players’ union agreed to a number of rule changes for 2020. Among them was a plan to reduce the scope of September roster expansion by capping rosters at 28 rather than a maximum of 40 for the final month of the season. 

In exchange, players will be granted a 26th roster spot in the other five months of the season. This is a significant break from tradition. The active roster size had been established at 25 players for more than a century.

A rule change of this magnitude will affect fantasy players and also those in simulation leagues, such as Strat-O-Matic or Diamond Mind. 

For the fantasy player, 28-man September rosters will bring clarity for two primary reasons. 

(1) Prospects who are called up in September to make their big league debuts are all but guaranteed to play. That means no more guesswork on whether top prospects will actually impact your team.

(2) Major league regulars who are banged up will now be placed on the injured list rather than exist in a state of limbo where they are perpetually probable or questionable in September. This will allow fantasy owners to execute better Plan B options in the thick of the fantasy playoffs in the event their starters are banged up.

The typical fantasy player will see neutral to positive effects from the new September roster rules, but the same is not true for simulation players in typical Strat or Diamond Mind formats that require players to make their major league debuts—or even reach a minimum number of at-bats or innings—to be draft eligible. 

This could have an adverse effect on the quantity of draft-eligible players, even if the overall quality of the player pool is similar. Because let’s face it: prospects such as Gavin Lux, Jesus Luzardo and Nico Hoerner would be strong candidates for September callups even with 28-man rosters. 

It’s the loss of second- and third-tier prospects, and those making brief big league cameos, who will be felt most acutely in sim drafts. This sort of player represents a wise dart throw in sim drafts, where player inventory and resource management are driving concerns.

That’s because sim league managers face strict usage rules that prohibit them from exceeding players’ real-life playing time. Thus players who simply provide mediocre at-bats or innings—whether now or in the future—have great value.

Not long ago, major league teams would call up prospects in September if they expected them to factor the following season. That isn’t as true today.

This year, the number of big league debuts in September bottomed out at 35 players, the lowest total since 1959, back when the number of major league teams was roughly half of what it is today.

Part of the dip in September debuts is a function of young players reaching the majors earlier in the season and making greater contributions than they once did. But an equally large factor in the diminishing number of September debuts is motivated by future considerations. Teams today are valuing future free agent eligibility more than present major league experience, especially with young position players who project to be impact hitters.

Kris Bryant, Ronald Acuña Jr., Eloy Jimenez, Vladimir Guerrero Jr. and Luis Robert were all denied September callups following Minor League Player of the Year or POY-caliber seasons they finished in the high minors. These players were held out so that their clubs could gain a seventh season of contractual control.

In a sense, these players were too good, too young. They all reached maturation long before their Rule 5 draft exemption windows closed. In other words, their clubs faced no external pressure to add these players to the 40-man roster and no internal desire to advance the date at which they first become eligible for free agency.

Alas, the days of prospects gaining valuable major league experience in September appear to be over.