With the 2025 season officially finished, it’s time to look ahead to 2026. The White Sox front office will rely heavily on their farm system and young players who are now established on the roster. While
they may bid low on a few free agents and hope they find another needle in a haystack with the second pick of the Rule 5 draft at the Winter Meetings, will the team be able to take the next step in their rebuild with this modest strategy?
To answer this question, it’s time to harken back to Bill James, the father of sabermetrics. As depicted in “Moneyball,” James’ model for predicting a team’s winning percentage equals runs squared divided by the sum of runs squared and runs allowed squared. This is known as the Pythagorean expectation.
Runs Scored^2 / (Runs Scored^2 + Runs Allowed^2)
To prove that the Pythagorean expectation is a useful model, I tabulated every team’s wins, runs scored, and runs allowed, and then calculated the Pythagorean expectation using the formula above. Then, I created a linear model to understand the relationship between winning percentage and Pythagorean expectation, as depicted in the below graph.
A low p-value of 1.03e-11 and R-squared value of 0.8133 indicate that the Pythagorean expectation is proportional to win percentage (or, in plain English, the Pythagorean expectation is an accurate model).
Now, let’s apply the Pythagorean expectation to Chicago’s rebuild. To make progress, the Sox should aim to win at least 70 games next year, propelling the team from awful to simply bad and equating to nearly a 30-game improvement in two years. Chicago ranked fourth-worst in runs scored (647) but only 10th-worst in runs allowed (742) last year. To win at least 70 games, according to the Pythagorean expectation, the Sox must do one of three things:
- Score more than 647 runs while holding runs allowed constant
- Allow fewer than 742 runs while hold runs scored constant
- Score more than 647 and allow fewer than 742 runs
The first scenario is most likely. According to Baseball-Reference, the Sox stranded 1,055 runners: 648 of them came from the first half of the season, with 201 coming from an abhorrent 16-38 stretch in March and April. They also left 10 or more batters on base 22 times, 13 of which were before the All-Star break. With the rookie jitters out of the way, the Sox should convert at least three of those stranded runners, scoring 650+ runs and winning 70 games if allowing the same number of runs.
The second scenario is harder to achieve but still possible; 367 of their 742 runs allowed were earned before July, and the rotation was responsible for 202 of those 367 runs. While neither the starters nor relievers truly clicked as a unit this season, the onus is on the rotation to improve. Per the Pythagorean expectation, the Sox should allow no more than 735 runs. This is reasonable and realistic, but is less probable to occur given Jonathan Cannon’s control problems, the loss of Martín Pérez, and Shane Smith’s volatility. Ky Bush and Drew Thorpe (who haven’t pitched since 2024 and are coming off of major surgery) as the rotation plug-ins makes this even less of a guarantee. To give themselves the best chance of reducing their runs allowed, the Sox should pick up a budget-friendly veteran starter who is more effective than Aaron Civale.
While of course the Sox should aim to score more runs while allowing fewer, the former is most practical given their payroll isn’t expected to grow significantly. In terms of young reinforcements, neither Hagen Smith nor Noah Schultz are expected to join The Show before the second half of the season.
The math indicates that the Sox should be able to make this next jump in their rebuild, but we’ll only find out once Opening Day comes around.
