Yes, Pennants Can Be Lost in April
When looking at most April stats, especially the basic ones, I spend a lot of time issuing disclaimers about small sample sizes. After all, any player can do just about anything in 25 or 50 or 100 plate appearances. I’m pretty confident that Joey Wiemer is not going to end the season as the NL MVP, and that Hunter Barco won’t finish the season with the worst WAR in major league history. But conversely, when we’re talking about standings, even if bad/good starts shouldn’t necessarily overconcern us about a player’s future, when it comes to teams, playoffs are determined by wins, which are cumulative numbers with razor-sharp margins. It’s not the end of the world if Cal Raleigh, because of his slow start, finishes with 38 homers instead of his projected 41 (ZiPS DC), but it may doom the Mariners if they underperform their projections by three wins.
The season is just a week old, but there are already sizable impacts in playoff probabilities around the league. To demonstrate this, I ran ZiPS overnight to get the updated playoff odds, so I could compare them to the preseason projections. Six teams have seen their playoff odds change by at least five percentage points. Here’s the full table, as things stand on Friday morning.
| Team | W | L | Pct | Div% | WC% | Playoff% | Preseason Playoff% | Difference |
|---|---|---|---|---|---|---|---|---|
| New York Yankees | 89 | 73 | .549 | 26.3% | 43.3% | 69.5% | 61.5% | 8.1% |
| Milwaukee Brewers | 88 | 74 | .543 | 42.8% | 21.3% | 64.1% | 56.8% | 7.3% |
| Houston Astros | 85 | 77 | .525 | 31.7% | 23.0% | 54.7% | 48.2% | 6.5% |
| Miami Marlins | 79 | 83 | .488 | 8.2% | 20.2% | 28.3% | 22.6% | 5.7% |
| Atlanta Braves | 85 | 77 | .525 | 21.5% | 29.6% | 51.1% | 46.5% | 4.6% |
| Texas Rangers | 82 | 80 | .506 | 18.6% | 19.7% | 38.3% | 34.2% | 4.1% |
| Toronto Blue Jays | 90 | 72 | .556 | 32.5% | 41.2% | 73.7% | 69.9% | 3.8% |
| Cleveland Guardians | 79 | 83 | .488 | 16.7% | 11.3% | 28.0% | 25.2% | 2.8% |
| St. Louis Cardinals | 77 | 85 | .475 | 5.6% | 11.1% | 16.8% | 14.5% | 2.2% |
| Kansas City Royals | 82 | 80 | .506 | 30.3% | 14.3% | 44.6% | 43.4% | 1.1% |
| Los Angeles Dodgers | 97 | 65 | .599 | 76.9% | 17.2% | 94.1% | 93.1% | 1.0% |
| Baltimore Orioles | 88 | 74 | .543 | 22.6% | 40.5% | 63.1% | 63.0% | 0.1% |
| Washington Nationals | 64 | 98 | .395 | 0.1% | 0.8% | 1.0% | 1.0% | 0.0% |
| Colorado Rockies | 60 | 102 | .370 | 0.0% | 0.0% | 0.0% | 0.1% | 0.0% |
| Los Angeles Angels | 67 | 95 | .414 | 0.6% | 1.4% | 2.0% | 2.2% | -0.2% |
| Cincinnati Reds | 77 | 85 | .475 | 5.3% | 10.4% | 15.7% | 16.5% | -0.8% |
| Pittsburgh Pirates | 79 | 83 | .488 | 10.5% | 15.5% | 26.0% | 27.1% | -1.1% |
| Philadelphia Phillies | 90 | 72 | .556 | 40.9% | 29.7% | 70.6% | 71.8% | -1.2% |
| Tampa Bay Rays | 73 | 89 | .451 | 0.8% | 8.4% | 9.1% | 11.0% | -1.8% |
| Chicago Cubs | 86 | 76 | .531 | 35.8% | 22.5% | 58.2% | 60.1% | -1.9% |
| Chicago White Sox | 71 | 91 | .438 | 2.2% | 2.2% | 4.3% | 6.6% | -2.3% |
| Minnesota Twins | 76 | 86 | .469 | 9.7% | 8.4% | 18.0% | 20.7% | -2.7% |
| Seattle Mariners | 88 | 74 | .543 | 45.9% | 21.3% | 67.2% | 70.1% | -2.9% |
| Arizona Diamondbacks | 81 | 81 | .500 | 6.5% | 27.0% | 33.5% | 36.7% | -3.2% |
| San Francisco Giants | 83 | 79 | .512 | 9.6% | 32.4% | 42.0% | 45.5% | -3.5% |
| New York Mets | 88 | 74 | .543 | 29.3% | 32.9% | 62.2% | 65.7% | -3.5% |
| Detroit Tigers | 84 | 78 | .519 | 41.3% | 13.1% | 54.4% | 58.1% | -3.7% |
| Athletics | 72 | 90 | .444 | 3.1% | 6.1% | 9.2% | 13.3% | -4.1% |
| San Diego Padres | 82 | 80 | .506 | 7.1% | 29.3% | 36.4% | 41.9% | -5.5% |
| Boston Red Sox | 88 | 74 | .543 | 17.9% | 46.0% | 63.9% | 72.7% | -8.9% |
To put this into context, just after last year’s trade deadline, only four teams saw their ZiPS playoff probabilities move at least five percentage points. The number was eight teams in 2024, three in 2023, and six in 2022. In other words, a week of games is about as impactful as a trade deadline.
Expectations for teams, by and large, haven’t changed. Not a single team saw its rest-of-season roster strength change by more than .007 of winning percentage, or 1.1 wins per 162-game season. It’s just what is baked into the cake. Those wins and losses have already been accumulated, and even a being of divine providence would have trouble changing them at this point.
ZiPS has been running standings projections since 2005, so I have a couple decades of data to pull from. To get a more empirical, less projection-y look at how easy it is to lose a playoff spot in April, I took all 83 teams with a median outcome of 90 or more wins going into the season. I didn’t include 2020, for obvious reasons. Just to head off one particular vein of argument, yes, 83 teams is a good number fewer than the 161 teams that actually won at least 90 games during the seasons in question. But that’s as it should be. We don’t expect all 30 teams to hit exactly their 50th-percentile median projections in a given season, but for three teams on average to hit their 90th-percentile projection, six to hit their 80th, and so on. If your median projections don’t have less variance than the actual results, you’ve likely done something terribly wrong with your model!
Anyway, I took the 90-win projected teams and looked at their worst performances in April. A full 26 of those teams finished the month with a losing record. And for most of those teams, it wasn’t just getting one of their fated bad runs over and done with early, an idea I usually deride as “Baseball Calvinism.” From a preseason average projected win total of 92.5 wins, they had an average finish of 85.2 wins, with slightly less than a third of them (8 of 26) finishing with at least 90 wins.
| Year | Team | Preseason Win Proj. | April Winning Pct | Final Wins |
|---|---|---|---|---|
| 2008 | New York Yankees | 95 | .483 | 89 |
| 2013 | Washington Nationals | 94 | .481 | 86 |
| 2010 | Boston Red Sox | 93 | .478 | 89 |
| 2012 | Philadelphia Phillies | 90 | .478 | 81 |
| 2009 | Chicago Cubs | 95 | .476 | 83 |
| 2021 | New York Mets | 91 | .476 | 77 |
| 2008 | Detroit Tigers | 91 | .464 | 74 |
| 2021 | New York Yankees | 95 | .462 | 92 |
| 2021 | Atlanta Braves | 91 | .462 | 88 |
| 2022 | Atlanta Braves | 90 | .455 | 101 |
| 2015 | Washington Nationals | 91 | .435 | 83 |
| 2019 | Boston Red Sox | 94 | .433 | 84 |
| 2019 | Washington Nationals | 93 | .429 | 93 |
| 2018 | Los Angeles Dodgers | 95 | .429 | 92 |
| 2009 | New York Mets | 91 | .429 | 70 |
| 2011 | Boston Red Sox | 93 | .423 | 90 |
| 2005 | New York Yankees | 91 | .417 | 95 |
| 2005 | Philadelphia Phillies | 98 | .417 | 88 |
| 2007 | New York Yankees | 95 | .391 | 94 |
| 2009 | Tampa Bay Rays | 90 | .391 | 84 |
| 2006 | Minnesota Twins | 90 | .375 | 96 |
| 2021 | Minnesota Twins | 91 | .375 | 73 |
| 2013 | Toronto Blue Jays | 94 | .370 | 74 |
| 2012 | Los Angeles Angels | 90 | .348 | 89 |
| 2013 | Los Angeles Angels | 93 | .346 | 78 |
| 2023 | St. Louis Cardinals | 91 | .345 | 71 |
Three of the 26 teams did manage to come back and beat their preseason win projection. Props to the 2006 Twins, who got off to a 9-15 start but still beat their preseason projection by nine wins.
What would the cost be of a bad April this year? To simulate bad Aprils, I ran the rest of this season 30 more times, each time making the team in question win four fewer games for the rest of April than projected, distributing the extra wins randomly in each simulation to the teams that it plays over the next four weeks. I then compared the change in each team’s playoff percentage, both to today’s projection and to its preseason playoff percentage. I’m also going to assume that the underperforming teams don’t actually see their team strength get any worse over those four weeks in order to isolate just how big a deal actual results are, with no change in expectation.
| Team | 4/3 Playoff% | Preseason Playoff% | Bad April Playoff% | Diff from 4/3 | Diff from Preseason |
|---|---|---|---|---|---|
| Milwaukee Brewers | 64.1% | 56.8% | 39.4% | -24.7% | -17.4% |
| Houston Astros | 54.7% | 48.2% | 32.2% | -22.5% | -16.0% |
| New York Yankees | 69.5% | 61.5% | 47.6% | -21.9% | -13.9% |
| Atlanta Braves | 51.1% | 46.5% | 30.9% | -20.2% | -15.6% |
| Texas Rangers | 38.3% | 34.2% | 18.8% | -19.5% | -15.4% |
| Miami Marlins | 28.3% | 22.6% | 10.0% | -18.3% | -12.6% |
| Kansas City Royals | 44.6% | 43.4% | 27.8% | -16.8% | -15.6% |
| Chicago Cubs | 58.2% | 60.1% | 41.9% | -16.3% | -18.2% |
| Toronto Blue Jays | 73.7% | 69.9% | 57.4% | -16.3% | -12.5% |
| Cleveland Guardians | 28.0% | 25.2% | 12.3% | -15.7% | -12.9% |
| San Francisco Giants | 42.0% | 45.5% | 27.6% | -14.4% | -17.9% |
| Baltimore Orioles | 63.1% | 63.0% | 49.0% | -14.1% | -14.0% |
| Pittsburgh Pirates | 26.0% | 27.1% | 12.0% | -14.0% | -15.1% |
| Arizona Diamondbacks | 33.5% | 36.7% | 19.6% | -13.9% | -17.1% |
| San Diego Padres | 36.4% | 41.9% | 23.7% | -12.7% | -18.2% |
| Philadelphia Phillies | 70.6% | 71.8% | 58.1% | -12.5% | -13.7% |
| Seattle Mariners | 67.2% | 70.1% | 54.7% | -12.5% | -15.4% |
| St. Louis Cardinals | 16.8% | 14.5% | 4.5% | -12.3% | -10.0% |
| New York Mets | 62.2% | 65.7% | 50.1% | -12.1% | -15.6% |
| Detroit Tigers | 54.4% | 58.1% | 42.6% | -11.8% | -15.5% |
| Cincinnati Reds | 15.7% | 16.5% | 5.4% | -10.3% | -11.1% |
| Minnesota Twins | 18.0% | 20.7% | 8.6% | -9.4% | -12.1% |
| Los Angeles Dodgers | 94.1% | 93.1% | 86.2% | -7.9% | -6.9% |
| Boston Red Sox | 63.9% | 72.7% | 57.4% | -6.5% | -15.3% |
| Tampa Bay Rays | 9.1% | 11.0% | 3.3% | -5.8% | -7.7% |
| Athletics | 9.2% | 13.3% | 4.2% | -5.0% | -9.1% |
| Chicago White Sox | 4.3% | 6.6% | 1.4% | -2.9% | -5.2% |
| Los Angeles Angels | 2.0% | 2.2% | 0.2% | -1.8% | -2.0% |
| Washington Nationals | 1.0% | 1.0% | 0.1% | -0.9% | -0.9% |
| Colorado Rockies | 0.0% | 0.1% | 0.0% | 0.0% | -0.1% |
With a bad April, every team in baseball except for the Dodgers becomes just about a coin flip or worse to make the playoffs. For teams like the Yankees and Cubs, both considered likely to make the playoffs coming into the season, it’s a serious drop-off, but relatively a flesh wound, as they have plenty of “outs” remaining to draw. For teams like the Cardinals, Reds, or Twins, a bad April is essentially an evisceration, with a strong majority of their playoff scenarios disappearing into thin air.
What does this all mean? If you’re a playoff contender, and you underperform in April, you should consider your record very seriously, even if your opinion of your team’s quality is completely unchanged. That means that adding wins is necessary now; don’t take a wait-and-see-where-we-stand-two-weeks-before-the-deadline approach. It can be hard to add wins this early in the season, but teams with bad starts really should be considering trying to catch lightning in a bottle with their minor leaguers — not just with their top prospects, but also the guys who are tearing it up in Triple-A. And if the opportunity to make a big trade does arise, struggling teams should take it. April really is the cruelest month.
Dan Szymborski is a senior writer for FanGraphs and the developer of the ZiPS projection system. He was a writer for ESPN.com from 2010-2018, a regular guest on a number of radio shows and podcasts, and a voting BBWAA member. He also maintains a terrible Twitter account at @DSzymborski.
You know what can’t be lost in April? Dan and his coolness. Thank you!
Great article! Braves certainly made the case for this last year.
And the Brewers in the opposite direction. They had a good team but a lot of short-term rotation trouble, so they traded for Priester to stabilize. They held water, were 4 games under in late May, and then just finished with the most wins in the game.
I don’t think anything about the 2025 Brewers can be used as an example of anything. It was the hottest team I have ever seen, with a few guys who looked like they were on the way out of the league suddenly morphing into average or better starting players (or in the case of Andrew Vaughn, morphing into Jeff Bagwell).
Excellent perspective. It is true that “Baseball is a marathon not a sprint” . But you can’t win a marathon if you walk the first four miles
Or what’s more accurate in this case, if you give your opponent a half-mile head start, it’s really hard to make that up.
“Baseball Calvinism” — are you referring to Calvinball or to the theological belief that God (probability) wills all?
I’m guessing it’s Calvinist theology.
That would mean it’s already been decided whether you are making the playoffs. You can’t change it, just that it is foretold that you will perform in a way that will make it so you are in the playoffs.
And if you don’t, then it was foretold that you wouldn’t.
I think that’s right, anyway. Predestination in Calvinist theology has been explained to me multiple times and I’m still not sure I fully understand it.
I always wondered how the Calvinists could preach pre determinism when most of Christian theology is based on free will and choice.
Unless your free will to choose right or wrong was predetermined? Were the Calvinists actually scientists with a strange set of lab coats? Free will, according to many scientists, is an illusion.
I can’t tie it back to baseball, unless we see Player A as the “chosen one” who will sacrifice something vital to make wins out of losses.
I can’t finish this train of thought. I’m not sure I am a true believer.
As I mentioned earlier, I am not confident in my interpretation of Calvinist predeterminism / the elect. But this is my understanding:
1) God is the source of everything.
2) Therefore, people are already saved or not. It has to be that way, otherwise God wouldn’t be the source of everything.
3) Because they are saved, they will act in ways that exemplify Christian teachings
4) Therefore, it is important to act in ways that exemplify Christian teachings. If you don’t, it means you haven’t been saved, and you aren’t part of the elect.
In other words, not only is your being saved predetermined, but so is your free will, and your free will means you will choose to live a righteous life. And somehow, this means that Calvinists still have choice?
Look, I’m not a Calvinist or even close to it, so I’m not going to say I buy it. To me, this gets causality almost entirely backwards. But as I like to say in response to almost anything about religion that doesn’t make sense logically or cannot be proved at all, “that’s why they call it ‘faith'”. I’m willing to give people a wide berth on their beliefs as long as nobody is getting hurt.
Scientists on the other hand…I can come down as hard on them as I want. The ones who think free will is an illusion do not understand the difference between deterministic and stochastic outcomes.
Meh. Free will can be technically existent, but practically non-existent. Yes, you can decide things but no, mostly your decisions are predetermined by the thousands of environmental, historical, and genetic variables that feed into them. That’s the illusion. You think you’re making a choice but really you’re just acting out a script.
It is true that people are way less independent and original than they think they are. “I am an independent thinker” they say, except they somehow arrived at the exact same conclusion with all of the same intermediate steps as millions of other people. Turns out all that stuff you just talked about matters a lot. A lot! Far more than people think.
I would rephrase your statement as: There is simply no way to evaluate the concept of free will without also evaluating the structures that people live in. After all, people’s decisions are both informed and constrained by environment.
(I also suppose that if someone wants to control for all of the variation in their brain activity that governs free will, then that person could conclude there is no free will. But then they would be enacting a jingle-jangle fallacy, I’m not sure whether it’s a jingle or a jangle)
or maybe Calvin Coolidge- be quiet & have a laissez-faire/figure it will correct itself approach to the whole season
Basically, if I understand the context correctly, it’s a restatement of the idea behind the “gambler’s fallacy”. If we were picking independently, and the team’s winning percentage was exactly what the pre-season prediction was, a team wouldn’t be more likely to win games in May because they were crappy in April. They’d just be more likely to end with a crappier record.
Could be a reference to the only Calvin in the league, Calvin Faucher on the Marlins. Despite a strong 2nd half of the season, missing the playoffs was predetermined from a slow start due to believing they didn’t have a better reliever than Calvin Faucher.
cc : Boston Red Sox
I think that they have gone from co-favorites to win the division to an 11% chance. Their playoff % on FanGraphs is under 50% now.
I was wondering when it’s wise to pack it in early and sell one year deal guys etc. earlier than the norm? I essentially was ready to see the opposite conclusion here that April underperformers should recognize the holes they have dug and get out in front of the trade market by selling.
I think it also makes sense to do that because teams with lower playoff odds should want higher variance early in the season and pending free agents are usually more predictable veterans.
The problem is that the buy-side of the market hasn’t really formed, so teams may not be willing to pay as much. I think the working assumption is teams will get more by selling a half season than 90% of a season, as absurd as that sounds. (Plus signaling the fans)
Really good article. Thanks Dan!
I agree with the thesis of the article but I do wonder what the error bars on these predictions are. How much of the delta between preseason and 4/3 projections for a given team is signal vs. random noise due to running a Monte Carlo? I’m pretty sure the delta for the Orioles is noise (0.1%). The delta for the Red Sox (-8.8%) seems like signal, the cost of not banking more than 2 wins in the first week while playing in a very competitive division. But where’s the breakpoint?
I sacrifice some accuracy for reproducibility, and use the same seed.
With a million seasons, you’re running into pretty small variances, and when it comes down to it, I think that value of the reproducibility outweighs what you lose. I dont’ particular care if a team has a playoff probability of 79.3% but “should” be 79.5%
Fascinating article Dan!
As a Sox fan I hope your conclusions are premature for this season. The Fenway Park scoreboard was quite odd to see the 5 teams with 5-4-3-2-1 wins. Hope that leaves room to rebound
Was also enlightening to see the 2010 & 11 Sox on the April list of strugglers. My recollection of those seasons is that they were frittered away late with numerous injuries in 2010 and of course the famous collapse in 2011.
Is it just hindsight that the whole 2011 collapse would have been avoided with a .500 April?
It’s darkly funny that the Rockies have already gone from 0.1% to 0.0% to make the playoffs