The Red Sox’ Shot at the Win Record

In 1906, the Chicago Cubs won 116 games against just 36 losses, becoming the only MLB team ever to win at least three-quarters of its games. Nearly 100 years later, in 2001, the Seattle Mariners equaled the Cubs’ win total but (because of the 162-game schedule) also posted 10 more losses. With their own loss last night, the 81-35 Boston Red Sox are currently on pace for 113 wins. While that total would not be a record, it would still represent the fourth-highest total in history — behind the aforementioned Cubs and Mariners in addition to the 1998 Yankees — and puts them within striking distance of the record.

In order to tie the record, Boston would need to finish the season on a 35-11 tear, a .761 winning percentage. That is, admittedly, a long shot. Consider, for context, that the Red Sox started the season by winning 17 of their first 20 games and still didn’t win their 35th of the year until after they had put up 16 losses. From May 24 through July 12, the team went 32-14 and, in an overlapping stretch from June 14 through Wednesday’s 10-5 win over the Blue Jays, the team went 34-12. In fact, backing up the recent run to June 11, the club went 37-12, a .755 winning percentage nearly identical to how they would need to finish the season and tie the win record.

While the Red Sox are incredibly talented, our projections don’t quite see a record as a realistic possibility, pegging Boston for a 108-win season. By going to our win-distribution graphs, we can get a better understanding of the team’s odds. What we see below are the win distributions for the AL East.

Half of the time the playoff odds are run, the Red Sox finish with 106 to 110 wins. That’s the most likely outcome based on our projections. Any one of those win totals would be one of the greatest in history. Since the league moved to the 162-game schedule in 1961 (and in 1962 for both leagues), only nine teams have even won 105 games. Only three of those have won more than the 108 games for which Boston is projected.

Most Wins in a Season Since 1961
Team Year W L W%
Seattle Mariners 2001 116 46 .716
New York Yankees 1998 114 48 .704
Baltimore Orioles 1969 109 53 .673
New York Yankees 1961 109 53 .673
New York Mets 1986 108 54 .667
Cincinnati Reds 1975 108 54 .667
Baltimore Orioles 1970 108 54 .667
Atlanta Braves 1998 106 56 .654
St. Louis Cardinals 2004 105 57 .648

If this post is starting to look familiar, it’s because I wrote a very similar one about a year ago for the Los Angeles Dodgers. Heading into action, a year ago today, the Dodgers had an 80-33 record and were on pace for a 115-win season. The club slowed down with a 24-25 finish to fall just short of the table above. Using a similar table to last season, here is where the best teams stood on August 1 in each respective season.

August 1 Pace for Winningest Teams
Team Year Aug. 1 W% Pace Actual wins Difference
New York Yankees 1998 .740 120 114 -6
Seattle Mariners 2001 .720 117 116 -1
Baltimore Orioles 1969 .692 112 109 -3
Boston Red Sox 2018 .688 111
New York Mets 1986 .677 110 108 -2
Atlanta Braves 1998 .648 105 106 1
Cincinnati Reds 1975 .645 104 108 4
St. Louis Cardinals 2004 .644 104 105 1
New York Yankees 1961 .626 101 109 8
Baltimore Orioles 1970 .625 101 108 7
AVERAGE .669 108 109 1
Average does not include Red Sox

Note that the Red Sox are near the top of the list, but also note that most teams at the top of the list tended to lose ground over the final months of the season. This isn’t too far off from the projected 108-win total. What the table above does not show are all the teams similarly situated to the Red Sox that failed to reach the 105-win threshold. To that end, see the table below, which includes all teams since 1961 that were on pace for at least 105 wins and how those teams ultimately fared.

Best August 1 Records Since 1961
Team YEar Aug. 1 W% Pace Final Wins Change Final W%
New York Yankees 1998 .740 120 114 -6 .704
Seattle Mariners 2001 .720 117 116 -1 .716
Los Angeles Dodgers 2017 .704 114 104 -10 .642
Baltmore Orioles 1969 .692 112 109 -3 .673
Boston Red Sox 2018 .688 111
Philadelphia Phillies 1976 .683 111 101 -10 .623
Cincinnati Reds 1970 .682 110 102 -8 .630
Baltimore Orioles 1979 .679 110 102 -8 .642
New York Mets 1986 .677 110 108 -2 .667
Detroit Tigers 1984 .676 110 104 -6 .642
San Francsico Giants 1993 .670 109 103 -6 .636
Detroit Tigers 2006 .670 109 95 -14 .586
Los Angeles Dodgers 1962 .664 108 101 -7 .620
St. Louis Cardinals 1968 .664 108 97 -11 .599
Baltimore Orioles 1966 .663 107 97 -10 .606
Chicago White Sox 2005 .663 107 99 -8 .611
Atlanta Braves 2003 .661 107 101 -6 .623
Atlanta Braves 1998 .658 107 106 -1 .654
Houston Astros 2017 .656 106 101 -5 .624
Los Angeles Dodgers 1974 .651 105 102 -3 .630
AVERAGE .678 110 103 -6 .638
Average does not include Red Sox

On average, teams lost about six games from their August 1 pace. Note that how teams performed down the stretch didn’t necessarily impact playoff performance. Thirteen of the 19 teams above made it to the World Series — including five of six teams that lost eight games or more off their pace since playoffs expanded in 1969 — and six won championships. The poor 1993 Giants team didn’t even make the playoffs, but that doesn’t seem too likely for the Red Sox this season. Both World Series participants from last year are on the list.

While we should note that every team above fell off their August 1 pace, we should also note that the Red Sox have actually improved their pace so far this season, winning six of the last seven games. Teams fall off the pace for a variety of reasons, including run-of-the-mill regression and a lack of urgency in September, by which time they have typically amassed a pretty large lead. Generally speaking, though, winning two out of every three games is really hard at the major-league level. By Pythagorean wins, the Red Sox have garnered three extra wins compared to their run differential, and using BaseRuns to strip out sequencing, the Red Sox have an extra seven wins with neutral-sequencing luck. By both of the latter measures, the Astros are actually ahead of the Red Sox this season.

To look at the actual chances of the Red Sox getting to 116 wins and tying the record, let’s take another look at the win distribution from earlier in this post.

The number of outcomes where the Red Sox tie or break the record is clearly not high, but in the simulations, Boston does get there on a decent number of occasions. The table below shows the percentage of outcomes where the Red Sox have at least a certain number of wins.

Red Sox’ Odds of Breaking the Win Record
WIns (At Least) Odds
97 100%
98 99.95%
99 99.88%
100 99.57%
101 99.03%
102 97.70%
103 95.70%
104 92.41%
105 86.78%
106 78.99%
107 69.52%
108 58.42%
109 46.46%
110 34.86%
111 24.07%
112 15.87%
113 9.01%
114 4.88%
115 2.15%
116 1.01%
117 0.42%
118 0.12%
119 0.04%
120 0.01%
Red line denotes 116-win mark recorded by 1906 Cubs and 2001 Mariners.

Our playoff odds give the Red Sox about a 1-in-100 shot at tying the win record and about 1-in-240 shot at breaking it. In one of the 10,000 simulations, the Red Sox won 123 games, which would still fall a single game short of the Cubs’ 1906 winning percentage. The odds are against the Red Sox, but if they play the final 46 games like they have the last 50, they could get pretty close.

We hoped you liked reading The Red Sox’ Shot at the Win Record by Craig Edwards!

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From 2000 to 2017, there were 15 teams with at least a 35-11 run. In those 18 years there were 540 team seasons, so the odds of a team going on such a run in a given season come out to 2.8%.

But the Red Sox have exactly one remaining opportunity to start a 35-11+ run, while in a 162 game season each team has 117, so the odds that a random team starts such a 46-game run on any given day is just 0.024%


this isn’t controlled for the quality of the team tho


Yes, but that effect isn’t significant enough to materially affect his observation. It’s extremely unlikely the Red Sox will tie or break the record.


Haha, this is like saying that it is highly unlikely that a hitter will put up a .400 AVG with the following reasoning: Just think of how low the odds are if you consider the batting averages of all hitters ever over sequences of 500 at-bats! Then when you take into account that the streak would have to start ON THE FIRST DAY OF THE SEASON the odds are unfathomable!

This is why I’ll stick to Craig’s analysis.

Captain Tenneal
Captain Tenneal

Is this…not pretty much true though? It might not be the best way to predict if someone’s gonna hit .400, but it sure seems like it would steer you toward the right answer of “almost certainly not.”