The concept of the playoff window is ubiquitous. We all know certain teams have their windows all the way open (Houston), while others are just now undoing the latch (Philadelphia) or are fighting to keep the sash from crashing down (Washington). With hard rebuilding periods more in vogue across baseball, the phenomenon seems to be even more pronounced than ever: Rather than bouncing in and out of contention every other year, more teams appear to be focusing on losing badly for four or five years, then spending a half-decade hell-bent on World Series rings.

But for all this talk about playoff “windows,” not much has been written about the idea of the window itself. How long does the average playoff window last? What’s the best way to open one? How, and how long, can a window be extended beyond its natural life? Are clearly defined windows becoming more common than they used to be? We’ll be addressing those questions — but a rather basic-seeming query must come first.

What is a playoff window, anyway?

We’ll start with the broad definition that a playoff window is a sustained multi-year effort to win playoff series, generally featuring the same core group of players and management. This definition excludes one-and-done playoff appearances. The 1993 expansion teams, notably, have never enjoyed a playoff window under our definition. The Colorado Rockies, after one postseason appearance in their first fourteen years, made an improbable run to the 2007 World Series, returned to the playoffs two years later and then went dormant until 2017. The Florida/Miami Marlins, meanwhile, have finished with a winning record just six times and somehow won the World Series twice.

Patrick Dubuque, in a Baseball Prospectus article that appears to be the only previous essay on the theory of playoff windows, includes the 2007-10 Rockies in his definition but admits the World Series run was about as planned-out as “a meteor landing on a car.” He writes that they “don’t really fit,” and we exclude that Rockies group here.

At the same time unexpected and unsustained playoff appearances are excluded, we must remember to count many years that resulted in disappointment — even in losing records. Teams like the 2012 Boston Red Sox and 2015 Washington Nationals, for example, were unambiguously within their “playoff windows.” That they lost anyway is their problem.

The idea that a window usually features the same identifiable big names — whether a star player or a consistent GM and ownership — helps us tease apart borderline cases. The 2010-2013 Boston Red Sox would otherwise be especially difficult to assess, as the team bounced rapidly between humiliating awfulness and a championship. Does a single 93-loss season mark the end of a playoff window if the following year ended in a shower of champagne? But we can separate the previous Red Sox run from the one that began in 2016 because of a new front office and a changeover in star power: Not counting David Ortiz’s final season, the only remaining star is Dustin Pedroia.

So we have a rough definition of a window. It has to be more than one year, but it can include the occasional face-plant. It usually will be marked by an internal consistency of stars: the Chipper-Maddux-Smoltz years in Atlanta, the Big Red Machine, Jose Bautista’s Blue Jays, the Time When Josh Hamilton Was Good. How long does such a run typically last? And what influences its length?

Let’s jump into the numbers. But first, a programming note: Playoff windows are subjective, and I had to make judgment calls. I’m also using the word “run” interchangeably with “window” to avoid monotony, even though a run is often also used to denote a single season.

Additionally, the criteria change every time the playoffs themselves change. It seems impossible, for this reason, to compare playoff runs in the Wild Card era with those that came before it. In the 1980s, teams won 100 games but went golfing in October. Now the Wild Card play-in game means the barrier to entry is lower than ever. For this reason, we’ll be restricting ourselves to the Wild Card era starting in 1995. It’s simply too early to tell how the play-in game, which first appeared in 2012, affects teams’ dynastic aspirations. Unless you’re the Pirates. Poor Pirates.

How long is a playoff window?

Since 1995, I identified 47 separate playoff runs by the MLB’s 30 teams. Miami, Colorado and Milwaukee appear to have enjoyed none, but the latter two are trying to make 2017 a new beginning. The Rockies and Brewers need to build on their success before we can count them in.

All MLB Team Playoff Runs Team First Run Second Run Third Run Arizona 1999-2003 Atlanta 1991-2005 2009-2013 Baltimore 1996-1997 2012-2016 Boston 1995-2013 2016- Chicago Cubs 2003-2004 2007-2008 2015- Chicago Sox 2003-2006 Cincinnati 1999-2000 2010-2013 Cleveland 1994-2001 2013- Colorado None Yet Detroit 2006-2014 Houston 1997-2005 2015- Kansas City 2013-2015 LA Angels 2002-2009 2014-2015 LA Dodgers 1994-1997 2004-2009 2013- Miami None Yet Milwaukee None Yet Minnesota 2001-2010 NY Mets 1997-2000 2006-2008 2015-2016 NY Yankees 1995-2012 2017- Oakland 1999-2006 2012-2014 Philadelphia 2005-2011 Pittsburgh 2013-2015 San Diego 1996-1998 2004-2007 San Francisco 1997-2004 2009-2016 Seattle 1995-1997 2000-2003 St Louis 2000-2016 Tampa Bay 2008-2013 Texas 1996-1999 2009-2013 2015-2016 Toronto 2015-2016 Washington 2012-

The most separate runs one team has achieved in the Wild Card era is three, a feat accomplished by four teams: the Cubs (2003-2004, 2007-2008, 2015-present), Dodgers (1994-1997, 2004-2009, 2013-present), Mets (1997-2000, 2006-2008, 2015-2016) and Rangers (1996-1999, 2009-2013, 2015-2016). It’s worth remembering that having more windows is not necessarily better — notice how many of these are short, and that only the Cubs won a championship.

Of the 47 playoff windows, seven are ongoing (BOS, CHC, CLE, HOU, LAD, NYY, WAS).

The other 40 can be divided into two categories: normal playoff runs and the monster decade-plus dynasties formed by the 1990s Braves, the curse-breaking Red Sox, the Joe Torre Yankees, and the Albert Pujols Cardinals. Those four teams distort the overall average so much that we will consider them separately.

The 36 traditional playoff windows were open for an average of 4.69 years each. Add the mega-dynasties back in, and that average swells to 5.95 years. So, basically, the typical playoff window is about five years long.

There’s a lot of wiggle room in there. The San Francisco Giants and Minnesota Twins had notably long runs, as did the Detroit Tigers while now-deceased owner Mike Ilitch tried heroically to win a title before he died. But eight of the 36 “windows” were just two years long, including Mike Trout’s first playoff appearances, the brief wonder that was Mark Prior, and the Rangers’ last-ditch effort to rebound from World Series heartbreak by replacing Ron Washington and two-thirds of his roster.

The five-year average is not exactly surprising. Each team gets six years of control for its talented young stars. After watching the Tampa Bay Rays, Houston Astros and Washington Nationals, we “know” a sustained run of playoff success begins by building a deep minor league system, calling up the young studs, and surrounding them with carefully-chosen veteran talent.

But is this always true?

How does a playoff window open?

The conventional rebuild model certainly has overtaken today’s playoff dynasties. Boston, Chicago, Cleveland, Houston, the Yankees and Washington built their teams by drafting young prospects and by acquiring them in trades. Only the Los Angeles Dodgers appear to be taking a different approach: They began their current window with Clayton Kershaw already in his prime, then added key free agents like Zach Greinke and Justin Turner and signed international stars like Hyun-Jin Ryu and Yasiel Puig.

Most interestingly, the Dodgers aggressively built a top farm system that did not exist at the start of their window. In 2012, the year before the current Dodgers run began, the team’s farm was ranked 19th by Baseball Prospectus, which called the hitting side “wafer-thin,” and 22nd by John Sickels. (The Astros ranked lower on both lists, by the way.) The only major name on Baseball Prospectus’ 2012 list of Dodger prospects was Joc Pederson. Four years and three playoff appearances later, that publication ranked their farm system the best in the league.

There is another factor that separates the Dodgers from the pack, of course: money. We’ll be talking more about that later.

So we know the “hoard prospects” model is currently favored by basically every team, even by the team that started winning before it started hoarding prospects. But what about past playoff contenders?

It’s hard to say. The 36 completed playoff windows started with an average batter age of 28.95 and ended with an average batter age of 29.77. The average pitching staff gets older by an even smaller margin (28.96 to 29.08). So playoff dynasties do finish older than they started, but the differences are small enough that I’m hesitant to make any grand conclusions.

Perhaps it would be better to focus on just star players, ignoring the revolving door of long relievers and backup catchers who might skew roster ages upward. Given how much we already need to discuss, that could be an analysis for another article.

The most extreme outlier in our theory’s favor is the 2008-13 Tampa Bay Rays — not a shock, since these Rays provided a template for the Astros and others to follow. The 2008 Rays were one of the youngest squads in the sample, averaging age 27; during the course of the window, the average Rays bat grew 2.5 years older, the average arm 1.5.

On the other hand, the 2009-13 Atlanta Braves got significantly younger over the course of three playoff appearances and a one-game Wild Card miss. The 2009 Braves were led by 32-year-old Javier Vazquez, 37-year-old Chipper Jones and 36-year-old Derek Lowe, but also had a brace of young talent, including Jair Jurrjens, Tommy Hanson, Brian McCann and Martin Prado. Four years later, McCann was still around and surrounded by a group of talented newcomers like Andrelton Simmons, Jason Heyward, Freddie Freeman and Julio Teheran — all 23 or younger. Vazquez, Jones and Lowe all had retired; the main veterans were Tim Hudson and Dan Uggla. A youngster named Craig Kimbrel was getting Cy Young votes.

In hindsight, what happened next is baffling. That 2013 Braves team looks like a dynasty in the making, and they still did on August 31, 2014. Melvin Upton Jr. was having a bad year, but the 72-65 Braves stood three games back in the Wild Card race with a month to go, on pace for a decent, if uninspiring, 85 wins. Then a disastrous September — including a 1-11 skid — led to the firing of GM Frank Wren and the dismantling of his youthful core. The ensuing rebuild was much faster than average, but did the Braves give up too soon?

The 2009-13 Atlanta Braves provide a rare example of a new group of talent emerging at the same time the last group got together for one final, remarkable victory lap. The 1997 San Francisco Giants followed another unorthodox strategy by trading for Shawn Estes and Jeff Kent. A year later, Ellis Burks, too, was added via trade. Trading frantically can be a viable strategy — but the Giants already had their most important piece: Barry Bonds. In a way, this plan can be compared to the current Dodgers’ Kershaw-centric dynasty.

Finally, the current rebuilding strategy is not as bold or new as some of its detractors suggest. The 2002 Anaheim Angels won a World Series with homegrown draft picks Garret Anderson, Darin Erstad, Jarrod Washburn, Troy Glaus, Troy Percival and John Lackey, all selected during a prolonged 1990s playoff drought with multiple 90-loss seasons. One David Eckstein waiver claim later, a championship squad was born.

What’s the secret behind a long window?

It’s money.

Payroll Increases During Playoff Runs 2000-present (in millions) Run Payroll at Start Payroll at End Percent Increase Atlanta 09-13 96.7 90 -6.93% Baltimore 12-16 84.1 147.7 75.62% Chicago Cubs 03-04 79.9 90.6 13.39% Chicago Cubs 07-08 99.7 118.3 18.66% Chicago White Sox 03-06 51 102.2 100.39% Cincinatti 10-13 76.1 106.9 40.47% Detroit 06-14 82.6 163.6 98.06% Kansas City 13-15 81.9 112.9 37.85% LA Angels 02-09 61.7 112.9 82.98% LA Angels 14-15 154.5 146.3 -5.31% LA Dodgers 04-09 92.9 100.4 8.07% Minnesota 01-10 24.1 97.7 305.39% NY Mets 06-08 101 137.8 36.44% NY Mets 15-16 101.3 135.2 33.46% Oakland 12-14 52.9 82.3 55.58% Philadelphia 05-11 95.5 166 73.82% Pittsburgh 13-15 66.8 90 34.73% San Diego 04-07 55.4 58.1 4.87% San Francisco 09-16 82.6 172.1 108.35% Seattle 00-03 59.2 87 46.96% Tampa 08-13 43.7 61.9 41.65% Texas 09-13 68.2 125.3 83.72% Texas 15-16 141.7 159 12.21% Toronto 15-16 125.9 136.8 8.66%

The Tigers spent money to prolong their playoff run to nine years. The Dodgers used prodigious cash to kick-start theirs, essentially buying a new squad via trade to create time for the rebirth of the farm system. The 1990s Yankees started with a historic core of young prospects, then threw money at them to ensure that they would never leave. The Nationals decided that Max Scherzer couldn’t hurt.

I tallied 24 playoff windows that both began and ended during or after 2000, the year from which Cot’s Baseball Contracts starts tracking Opening Day payrolls. In that time, the average team’s payroll rose 41.5 percent from the beginning of a playoff window to the end. Only two teams saw decreases: those anomalous Atlanta Braves (one suspects they might still be contending had they made bigger, smarter investments prior to 2014) and the 2014-15 Angels, who passed a quiet offseason in which they, financially, exchanged Howie Kendrick and Sean Burnett for Matt Joyce.

It’s hard to compare payroll increases and window length because of salary inflation and ballooning TV deals. The longer a run, the more inflation will affect it. The Minnesota Twins quadrupled their budget during the Mauer-Morneau years, which coincided with a decade in which more and more money flowed throughout the sport.

It’s still worth observing that the 2009-16 Giants, 2005-11 Phillies, 2001-10 Twins, 2002-09 Angels and 2006-14 Tigers all saw payroll increases of at least 72 percent. Various Cubs, Mets, Padres and Blue Jays teams made below-average adjustments to their budget and enjoyed below-average runs in the postseason. Notably, the Braves were the only team to enjoy a below-average payroll adjustment while not also suffering from a shorter-than-average playoff window — and even then, we suspect their window could have been longer.

This analysis excluded the current playoff runs, but note that the Dodgers, who maintained a relatively steady payroll during their mid-2000s window of contention, have sharply increased and then sharply decreased budgets during this one. The 2018 Dodgers are the club’s lowest-paid group in six years. It’s another way in which this team’s playoff run stands out from the rest of the league’s.

Can’t you lengthen a window by replenishing the talent pool every few years through trade and continued player development, rather than through budget increases?

Sure. The 2000 and 2006 Moneyball Oakland Athletics had just two players in common, Eric Chavez and Barry Zito. Brad Penny was the only constant in the mid-2000s Dodgers run.

But this kind of success is rare, for a simple reason: It’s hard. The front office has to sign free agents who don’t turn into pumpkins, execute successful trades, move on from players who might be at their peaks in order to make room for younger talent, develop prospects and in general be damn good at their jobs.

And then there are the four mega-dynasties.

Hey, yeah! Aren’t you going to talk about the Yankees, Red Sox, Braves and Cardinals?

Of course. The Yankees followed the blueprint above but with the benefit of enormous sums of cash. Once they developed their young core, they bolstered it through international amateur signings and used prospects as trade chips for major-league talent. And they spent money.

The Cardinals may have been in a small market, but even they increased their payroll 39 percent between 2000 and their 2006 championship. By 2015, the payroll had effectively doubled since the team’s run began.

These four teams share a common element that is nearly impossible for the average team to replicate: long-term deals with first-ballot Hall of Famers. Not everybody gets to have Albert Pujols, Pedro Martinez, Derek Jeter and Greg Maddux. But if you do find a way to develop or acquire a Hall of Fame player at his peak, that factor alone can significantly lengthen your playoff window. (See also: the Biggio-Bagwell Astros, Harper-Scherzer Nationals and Barry Bonds Giants. So far, Mike Trout and Joey Votto have been near-historic exceptions.)

Are windows more common than they used to be?

This question is another way of looking at competitive balance, which is a whole different kettle of popcorn. (For the record, the answer is unclear, and the league is small enough that variation may be random.)

Ten years from now, it would be interesting to look back on the Wild Card era and see if the average playoff window has gotten longer since the late 1990s. That could indicate smarter GMs, more Wild Card turnover, or a decrease in competitive balance.

What about winning it all?

Only one team since 1995 has won a World Series outside a conventional “window,” and they have somehow done it twice. Does anyone believe the Marlins are a role model?

All four of the superteams won during their reigns, the Braves once and the others at least twice. For everyone else, the odds are still daunting: Only six of the 36 completed, ordinary playoff windows resulted in championships. And of the seven ongoing runs, only the Cubs and Astros have won so far. This game is hard.

Conclusions

Some of our conclusions are unsurprising. Developing a talented young core is smart, teams that grow younger during their windows are rare, it’s better to have longer windows than more frequent ones, spending money helps, and Hall of Famers are good.

Others might be more intriguing. About one-quarter of playoff runs last just two years. It seems like we can reliably assume that about one-third of the league will be contending for multi-year success at any given time, in addition to anybody hoping to strike it lucky. Sustaining a dynasty without boosting the payroll is nearly impossible. The Atlanta Braves may have gone through an entire rebuild cycle in reaction to a single lackluster month.

There is more research to be done. Would our analysis of the average roster age over the course of a playoff run be different if we focused on star-caliber players, excluding middle relievers and pinch-hitters? And the problem of how to build a long playoff run without raising payroll also merits further investigation.

All of which is a very long way of answering the simple, painless question I had originally thought I was asking: How long is a playoff window?

About five years, it turns out. But there’s a lot more to the story than that.