In September, Major League Baseball plays a different game than in the other months of the regular season. With teams allowed to carry as many as 40 active players, the dynamics of every game are different. Every team has more pitching depth. Every team has better pinch-hitting and defensive replacement options. Since pitching depth and quality bench players are two of the game’s most scarce resources these days, the opening up of the rosters can force us to totally reevaluate teams on whom we were just starting to really get a handle.

About this time for each of the past few years, there have been calls for some sort of countermeasure, some game-to-game roster limitation that would turn September from an analog of baseball’s regular season to a more honest extension of it. I’m all for that, or alternatively, for replacing years of jail time for nonviolent crimes with a mandatory sentence of watching Terry Francona manage a close game in September. Until such a change comes, teams will continue to generate box scores that look like your history notes from freshman year of high school: loaded with more names than one can possibly keep straight, painstakingly footnoted, indented every so often for good measure, but ultimately, indecipherable, even to their creators.

Since that’s the case, though, we might as well take stock of the various ways in which teams try to leverage September call-ups, and even late-August additions, into improved chances of winning a championship. (For today, that’ll be the focus. We know that non-contending teams can use this month to evaluate players who sit on the fringes of their future, but there’s nothing strategically or economically interesting about that. There’s no cost involved in that, for those teams, except the relatively meaningless extra cash paid to those who get big-league paychecks for a few extra weeks.) There are four fundamental ways in which a team can help itself by making trades in late August and calling guys up in September:

Genuine Roster Improvement – These are rare but important cases. Most teams who have the means and motivation to make significant changes and get better for the stretch run do so by the end of July, but some teams can’t make their roster math work to call up a certain player until September 1, and others find a player who slipped through waivers (or pounce on a guy whose team is looking to offload him) and upgrade at the end of August. Obviously, nothing changes the calculation of a contender’s chances of reaching or thriving in the playoffs quite like making a tangible step forward in team talent.

Rest – It’s often the case that a team has little to gain in September, and only needs to avoid losing a healthy lead. In those cases, given the way baseball works these days, it’s very valuable for a club to have some spare parts to which they can spread some of the workload down the stretch, allowing them to field a fresher unit come October.

Tactical Advantage – A lot of guys can help you win certain games with their situation-specific skills, but aren’t good enough at most of baseball to play at all when the normal roster structures are in place. Some teams emphasize having guys like this around more than others, and some must scramble to gather them up when it becomes clear that winning those narrow games is going to matter a lot. The gap in the quality of these specialists from one team to another can be significant.

Development and Evaluation – There are times when it’s sufficiently important for a team to find out what they have in a given player, or to foster that player’s development by giving them playing time and exposing them to the highest possible level of competition, that they elect to call a player up and given them a shot even in the high-stakes setting of a late-season race for the playoffs. As I said, it’s less interesting to watch young players like these play for bad teams every September. The sample sizes are much too small to tell us anything, the atmosphere into which those players are stepping is a long way from the one in which they’ll be asked to succeed when it actually matters, and there’s no strategy or nuance to the decision to allow those guys to play. For good teams, though, it’s an interesting balance of competing incentives, and a fun set of dilemmas to parse.

It would be exhausting and repetitive and analytically void to wade through all of the September additions made by every contender. (Trust me. I tried it. Twice. Oof, it was bad, you guys.) Let’s just run through each of these areas of potential profit in September roster management, and highlight a couple of interesting case studies that have popped up this week.

Genuine Roster Improvement

The Cubs traded for Austin Jackson, a move that got a fair amount of attention but not nearly the level of praise it deserved. Chicago needed a replacement for Jorge Soler in right field (at least against left-handed pitchers), insurance against a Dexter Fowler injury, and a much, much better set of options off their bench on the average night. Jackson provides all of that. He was the best defensive outfielder on the team the moment he arrived. He struggled in Seattle for over a year, but has too long a track record of success to let that (mitigated) failure sour anyone on him. He works hard and runs the bases aggressively. He’s a role player of a caliber only the Dodgers can match.

Steven Matz returned to the Mets, a sort of incidental upgrade, but not an insignificant one. Matz was simply coming off the DL, but logistically, he couldn’t really do it until the rosters expanded. Matz is New York’s fourth starter, basically, and bumps Bartolo Colon and Jon Niese closer and closer to relief roles. Add his return to the long list of reasons the Mets shouldn’t worry about the Nationals catching them this month.


Obviously, it’s easiest to emphasize rest when one has nothing (or very little) to lose, and nothing (or very little) to gain. The Cardinals used Mitch Harris for two innings on Tuesday night, the second of which was the top of the ninth in a tied game. Both the Cardinals and the Royals called up catchers with just enough to them to allow them to play in blowouts and start the occasional day game after a night game, taking pressure off of both of their incumbent backstops. Yadier Molina is getting old, thought his performance in the second half has rarely shown it, and could use a few innings off to keep his odometer low for October. Salvador Perez could use a three-month vacation in whatever part of the world it is from which the latest trendy massages come, but will probably have to settle for “only” catching 135 games this year.

The Cardinals also called up Marco Gonzales to make a start on Tuesday, and (after he pitched very poorly) sent him down in favor of Tyler Lyons on Wednesday. One can only assume that the idea is to lengthen the starting rotation there, allowing Carlos Martinez and Michael Wacha to enter the playoffs fresher and with fewer innings on their arms than they otherwise would.

Tactical Advantage

Exemplars of this kind of addition are everywhere. The Yankees, Cubs, and Royals called up true pinch-running specialists, guys whose only job will be to steal critical bases despite the opponent being fully aware of that imperative. The Mets and Blue Jays appear to have added modified versions of that archetype, in Eric Young, Jr. and Dalton Pompey, respectively.

The Twins called up Kennys Vargas, a switch-hitting slugger whose struggles early in the season have (perhaps unfairly) dimmed the collective memory of his strong rookie showing last year. Vargas is a bad defensive first baseman, and can’t even try it anywhere else. Roster math pushed him to the minors two and a half months ago, because he couldn’t be the regular DH and anything less was too little to get out of a roster spot. With the expansion of rosters, though, that no longer holds true, and Vargas becomes a pretty good pinch-hitting option for Paul Molitor.

The Angels recalled both Wesley Wright and Mike Morin, a lefty and a righty who can only get out same-handed batters, and should never, ever face an opposite-handed batter of any consequence. That kind of player doesn’t fit well on a 25-man roster, but one of each for the fifth or sixth or 14th inning of a game when the matchups work out, with 40 roster spots available? These two not only work, but make one very good pitcher, in composite.

Development and Evaluation

We can sit and wait for the Dodgers to call up Corey Seager all we want, but for now, the most interesting case studies of September in this regard are the two power prodigies with the huge strikeout issues: Javier Baez and Joey Gallo. Both could feasibly work their way into the regular lineup, and even the playoff lineup, for their teams. Both could also be left rotting on the bench, or worse, actively hurting the team by contributing an empty pinch-hit plate appearance every day. The Cubs and Rangers each have sufficient flaws to make calling up their high-risk studs for an audition worthwhile, but neither has so much margin for error that they should be expected to let their guy take his lumps for long.

The Cubs have six and a half games to play with, so they might be open to letting Baez fail and learn on the job at second base, but by October 7, they need to have a firm answer as to who will start and where. That might force them to spread the at-bats around, focusing more on allowing one of Baez, Starlin Castro, or Tommy La Stella to prove themselves worthy of the role than on making sure Baez sees and adapts to tough big-league arms.

The Rangers, of course, have no margin for error whatsoever. As I write this, they’re locked in a tied game with the Padres [editor’s note: they won], trying to avoid falling into a tie with the Twins for the second Wild Card Game entry [editor’s note: they didn’t]. Gallo has the kind of bat that can win a game for you, but he also has the kind of holes that can lose one. Gallo started in left field Wednesday night and struck out three times in three trips. Texas can’t let him do that very often. Will Venable will get the starts in left more often than Gallo will, unless Gallo proves it shouldn’t be so.


This brand of September baseball gives us a better October. Teams have often been playing an October version of the game for at least a week or two by the time the playoffs start, and those who don’t expend every ounce of their energy on simply reaching the tournament have used their time to rest and maximize their players’ health. Rare are the games, even during the Division Series, in which either team looks unprepared or unable to meet the raised level of intensity and atmosphere we want from the playoffs.

This way of doing things also rewards the very things we’re starting to understand as most important to the modern game, even over the long haul of the regular season. Organizational depth, aggressive roster-building, and a healthy two-way line of communication between the front office and the manager are often the only things that really allow a team to distinguish itself anymore, and the expanded-roster model of September baseball emphasizes those tremendously.

I still think it makes for ugly, protracted, often overwrought baseball. Those who balk at this model for reasons of competitive balance or consistency, though, are either missing those two points, or underestimating their importance.

Thank you for reading

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