The 10-Day Disabled List Is a Beautiful Thing

The collective bargaining agreement on which the players and owners have just tentatively come to terms didn’t move the needle too much in the grand scheme of things. The changes that occurred were more akin to trimming the branches on a bonsai tree than they were clear-cutting a forest. But one interesting alteration was the replacement of the 15-day disabled list with a 10-day variety. This be interesting in a few ways.

I have to say, my first thought was very much:

The 15-day disabled list was instituted in 1966. That’s a long time! That makes the 15-day disabled list older than the Big Mac. Oh man, I could go for a Big Mac right about now. Meat, cheese, special sau… Wait, where was I? Oh, yes: disabled-list history. One thing becomes clear when you look into it: identifying the optimal “span” of dates for it is as much art as science. In fact, the new 10-day DL isn’t really new at all, but more a circle of life sort of thing. Consider this point, from a 2013 piece at Baseball Prospectus by Corey Dawkins and Rebecca Glass:

“Disabled” or “injury” lists go all the way back to the early 1900s. Rosters held only 21 players, and several managers and National League clubs were upset at how the strict limit punished those unhealthy or unfortunate—something, perhaps, that should not be ignored today. In response, the National League created the first official disabled list on July 12, 1915; it allowed players to be removed from the roster for a ten-day recuperation period. Even though they were not allowed to play, injured players could remain with the team as a “coacher.”

So, while it will be an adjustment, it’s all just a little bit of history repeating. And, for the position players, it may not make much of a difference. Over at RotoGraphs, the venerable Jeff Zimmerman broke out a special MASH Report to crunch the numbers. Jeff looked into his disabled-list database and found that only 14% of position-player trips to the disabled list since 2002 ended in precisely 15 days — that is, 457 from a sample of 3,360:

Breaking the numbers down further, 457 15-day instances occurred over the past 15 years so it works out to 30.5 instances per year, or about once per MLB team per year. The possible time gained off shorter DL stints isn’t that much. The owners will like seeing these few, hopefully healthy, players back sooner but the difference won’t be measurable.

The change for pitchers may be a little more impactful, however. As Mike Petriello noted yesterday at, the average major-league start last year was 5.2 innings. But let’s break that down a little bit.

Innings Pitched by # of Games Started, 2016
1 to 5 87 230 1,045.1 4.5
6 to 10 47 372 1,838.1 4.9
11 to 15 34 439 2,234.1 5.1
16 to 20 25 476 2,629.1 5.5
21 to 25 32 740 4,165.1 5.6
26 to 30 39 1108 6,467.2 5.8
31+ 46 1491 9,032.1 6.1

The way to read the table above is that 87 pitchers last year started between one and five games. As a group, that came out to 1,045.1 innings pitched across 230 games, for an average of 4.5 innings pitched. Not a lot. As you can see in the right-most column, this average innings figure increases substantially the more regular a starter is. The best starters in the game still take the ball for six — or nearly six — innings a start.

Now, let’s go back to Mike’s piece for a second, as he eloquently lays out why this innings pitched per start figure is important:

To start with, consider how this might affect how teams approach the starting rotation. In a five-man rotation, here’s what a regular starting pitcher’s schedule looks like following a start:

Days 1-4: Rest
Day 5: Start
Days 6-9: Rest
Day 10: Start

Simple, right? Two starts every 10 days. Now think about how that looks with even a single day off included. And, realize that we may get additional off-days under the new CBA, according to’s Richard Justice, who reported that “beginning in 2018, the regular season will begin in mid-week to create additional off-days during the schedule.” So while we don’t know how many more days off are coming, it seems that it’s at least “more.”

We’ll randomly assign the team’s off day to Day 7 in our hypothetical, but it could really just be about any day:

Days 1-4: Rest
Day 5: Start
Days 6-10: 4 days rest, 1 team off day
Day 11: Start

If you’ve got a fifth starter who maybe isn’t quite right physically, what would you rather do? Would you rather let his 4.5-5.1 innings eat up a roster spot, or would you like to put him on the disabled list and get someone healthy in to take his spot? I think we all know the answer to that, especially since, if a pitcher’s banged up, 4.5-5.1 innings might represent a best-case scenario for him. Even if a club were to call up a reliever in his place, there’s a decent chance that the replacement is going to log five innings over a 10-day period.

I know what you’re thinking: what’s the difference? You could just send that fifth starter to the minors. Fifth starters generally don’t hold sufficient cachet with a club to directly oppose a demotion. That “1 to 5” starts list is jam-packed with fungible guys like Christian Bergman, Roenis Elias and Nick Tepesch. But consider, as Dave Cameron pointed out to me on Slack yesterday: when you option a player to the minors, he has to remain in the minors for 10 days. So, the 10-day DL will work in the same fashion, but now both the injured player and team benefit.

The player benefits because he gets to cash major-league checks for 10 days that he wouldn’t have before. He also doesn’t have the record of being optioned back to the minors on his resume, which can sometimes affect players in arbitration hearings, should they make it that far in their careers. For the team, it gives them the flexibility of retaining more option assignments before they have to expose that player to outright waivers. This gives them flexibility not just with the management of their roster, but will also make these types of players more attractive in trade, as their future team will likely get more out of these players if they have those option assignments left. That final point is likely really minor, but it’s there nonetheless.

We can look at one example that illustrates how this new DL could be utilized. On August 16, Eduardo Rodriguez was firing on all cylinders. In his first four innings in Baltimore, he pitched no-hit ball, walking just Chris Davis in the second while striking out seven. He struck out Jonathan Schoop, Manny Machado and Mark Trumbo in order in the fourth. When he came out in the fifth inning, however, he tweaked his hamstring. He left in the middle of his at-bat against Steve Pearce and wouldn’t pitch for 12 days.

Rodriguez spent those 12 days on the active roster, because at the time, the team was hopeful he would make his next start. When a guy no-hits a division rival for nearly half a game, you don’t want to send him back to Triple-A. Unfortunately, on the 21st, Rodriguez remained unable to pitch, and the team called up Henry Owens to make the start, sending down Deven Marrero to get Owens up. Now, Marrero’s utility was minimal on a Red Sox team with a full complement of starting position players, but the point is that Boston went into that game with one fewer player than they should have had, because Rodriguez was swallowing a roster spot whole. And as I noted earlier, if Rodriguez had gone, he probably would have more limited than his normal 5.35 IP/GS.

These are not necessarily situations that we can easily quantify, as we never had a reason to in this manner before. But these scenarios happen frequently, and now teams can account for them while keeping major-league players in the major leagues thanks to the shorter DL time. The overall balance of this CBA may tilt toward the owners, but the shortened DL time is a beautiful thing for the players and the stewards of major-league rosters who are just trying to get through the season with as few headaches as possible.

Paul Swydan used to be the managing editor of The Hardball Times, a writer and editor for FanGraphs and a writer for and The Boston Globe. Now, he owns The Silver Unicorn Bookstore, an independent bookstore in Acton, Mass. Follow him on Twitter @Swydan. Follow the store @SilUnicornActon.

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I would think the biggest impact of a 10 day DL is that you can now put any of your starters on the DL if they experience a relatively minor injury and only have them miss one start, factoring in one off day. With a 15-day DL you’re looking at missing two starts. So, a team would now be more apt to use the DL and call someone up for 10-11 days.


A lot of ink has been given to SPs, and that’s fair because that’s probably the biggest way a team gains an advantage under this new rule, but many teams (especially the Dodgers last year) had a rotating crop of young RPs that were taking the shuttle back and forth. If this kind of rotation becomes the norm, it’ll be a lot harder to rack up service-time (for pensions among other things)for relievers. If they can be DL’d instead of sent down to get a fresh arm in there, then that accumulation is a bit more constant- which should help them out quite a bit.