Before October Began: How BBMI’s Playoff Odds Held Up
All four bye teams reached the Championship Series. BBMI’s top American League pennant pick made the World Series. And the Brewers won it all despite entering October with a 12.8% title chance. Here’s what BBMI got right, what it missed, and how its forecasts compared with the betting market.
Milwaukee finished the job on October 28. The Brewers beat Tampa Bay 4–1 in Game 5 to win the franchise’s first World Series title, with William Contreras earning Series MVP. But this review starts a month earlier, before anyone knew how October would unfold.
On September 28, before the first Wild Card game, BBMI’s Bracket Pulse gave the 103-win Brewers a 12.8% chance to win the title. That was third among the 12 playoff teams, behind Los Angeles (24.6%) and Tampa Bay (15.5%). Milwaukee was favored to reach the NLCS, but the Dodgers were more likely to win the National League pennant. The eventual champion was a credible contender, not BBMI’s title pick.
We kept that September 28 forecast intact. What follows is the original board alongside the final results, not odds reconstructed after the fact. One postseason helps us evaluate specific calls, but cannot establish long-run calibration. Today’s Bracket Pulse shows the completed bracket; the September 28 probabilities are preserved in the historical data file and reproduced in the table below.
| Club | Seed | Record | Reach DS | Reach LCS | Reach WS | Win title | Result |
|---|---|---|---|---|---|---|---|
| Dodgers | NL 2 | 100–62 | 100% | 61.1% | 38.8% | 24.6% | Lost NLCS 0–4 to Milwaukee |
| Rays | AL 1 | 98–64 | 100% | 54.4% | 33.3% | 15.5% | Lost World Series 1–4 to Milwaukee |
| Brewers | NL 1 | 103–59 | 100% | 57.1% | 23.4% | 12.8% | Won World Series |
| Yankees | AL 4 | 93–68 | 59.4% | 29.7% | 18.2% | 9.0% | Lost ALDS 0–3 to Tampa Bay |
| Astros | AL 3 | 81–81 | 59.8% | 38.0% | 18.5% | 8.4% | Lost Wild Card 0–2 to Chicago |
| Phillies | NL 6 | 88–74 | 53.6% | 20.8% | 11.6% | 6.2% | Lost Wild Card 1–2 to Atlanta |
| Guardians | AL 2 | 85–77 | 100% | 44.4% | 15.6% | 5.0% | Lost ALCS 2–4 to Tampa Bay |
| Braves | NL 3 | 94–68 | 46.4% | 18.0% | 8.8% | 4.7% | Lost NLDS 1–3 to Los Angeles |
| Cubs | NL 5 | 89–73 | 45.5% | 20.9% | 8.6% | 4.4% | Lost Wild Card 0–2 to San Diego |
| Padres | NL 4 | 91–71 | 54.5% | 22.0% | 8.8% | 4.3% | Lost NLDS 1–3 to Milwaukee |
| Red Sox | AL 5 | 87–75 | 40.6% | 15.9% | 8.4% | 3.4% | Lost Wild Card 0–2 to New York |
| White Sox | AL 6 | 84–78 | 40.2% | 17.6% | 6.0% | 1.8% | Lost ALDS 2–3 to Cleveland |
Each percentage is the share of 10,000 simulated postseasons in which the club reached that round at all, whoever it played along the way. DS is the Division Series, LCS the League Championship Series, WS the World Series. Reach DS is 100% for the four clubs with first-round byes. Shaded cells mark rounds the club actually reached. Clubs are sorted by title odds; records are final regular-season records.
Astros 59.8% (lost 0–2 to the White Sox) · Phillies 53.6% (lost 1–2 to the Braves) · Cubs 45.5% (lost 0–2 to the Padres) · Red Sox 40.6% (lost 0–2 to the Yankees)
Each card shows the club’s chance, as of September 28, of reaching that round at all, the same figures as Exhibit 1. Outlined cards won the series; the bar fills to the probability. For scale, an equal bye club would reach the LCS 50% of the time and the World Series 25%.
Wild Card: two favorites advance, two underdogs win
BBMI made Houston (59.8%), New York (59.4%), San Diego (54.5%) and Philadelphia (53.6%) narrow favorites in their Wild Card matchups. New York and San Diego advanced; Houston and Philadelphia did not. None of those four series was close to a sure thing.
Chicago swept Houston, while Atlanta beat Philadelphia in three games. Across the four matchups, BBMI’s probabilities added up to 2.27 expected wins by the favorites. The actual result was two. That is close to the expectation, but four series are far too few to establish accuracy by themselves.
Bars show the board’s chance that the favorite would win its best-of-three series. The black tick marks 50%, a coin flip. Green bars advanced; gray bars went out. Expected favorites advancing is the sum of the four probabilities.
There is one important distinction: BBMI’s separate, game-by-game Wild Card preview favored Atlanta at 57% after incorporating projected pitching plans. The September 28 bracket board had Philadelphia at 53.6%. Both numbers were published before play; they are different forecast snapshots and should be graded separately.
Division Series: four for four on the bye teams
The strongest round-level result came in the Division Series. BBMI gave each bye team the best chance in its quarter to advance: Tampa Bay 54.4%, Cleveland 44.4%, Milwaukee 57.1% and Los Angeles 61.1%. All four advanced. Multiplying those probabilities gives about an 8.4% chance of a four-for-four outcome, assuming the four quarter outcomes are independent as modeled. The result was uncommon, even though each club was the individual favorite.
Bars show each bye team’s chance, as of September 28, of winning its Division Series and reaching the LCS; all four did. An equal bye club would be at 50%, the black tick. The last bar multiplies the four, since the quarters of the bracket do not meet before the LCS.
Tampa Bay swept New York, Milwaukee beat San Diego in four, and Los Angeles eliminated Atlanta in four. Cleveland lost the first two games to Chicago, then won three straight. Its pitchers struck out 21 White Sox hitters in Game 5, a major league record for a nine-inning game. BBMI gave Cleveland the best chance in its bracket quarter, but the series went the full five games.
Championship Series: right pick in the AL, wrong pick in the NL
Tampa Bay entered October as BBMI’s leading AL pennant candidate at 33.3%. That call held up. The Rays rallied from a 2–1 ALCS deficit to beat Cleveland in six, finishing with a 7–3 victory on October 19. Freddy Peralta allowed one run in 5⅓ innings and earned series MVP honors.
The National League was the big miss. BBMI gave the Dodgers a 38.8% chance of winning the pennant, versus 23.4% for Milwaukee. Instead, the Brewers swept Los Angeles. Milwaukee trailed at some point in every game and still completed the sweep. Los Angeles had the best individual chance of taking the NL pennant, but its 38.8% probability also meant a 61.2% chance that another club would win.
World Series: Milwaukee 4, Tampa Bay 1
Before the playoffs, the most likely World Series matchup on BBMI’s board was Dodgers–Rays, at about 12.9%. Brewers–Rays was roughly 7.8%. These are joint probabilities for the two pennant winners, calculated from the separate league outcomes.
Milwaukee’s 12.8% overall title chance needs context. Conditional on reaching the World Series, BBMI’s simulation gave the Brewers about a 54.7% chance to win it, averaged across potential opponents. The bigger obstacle was getting through the National League bracket, especially Los Angeles. The Rays’ corresponding conditional championship figure was 46.5%.
Bars show the September 28 chance of reaching each round at all. Green marks a round the club reached; gray, one it did not. “If it reached the World Series” is the title chance divided by the pennant chance: the share of simulated World Series appearances the club won, averaged over every possible opponent. An equal club would win 50%.
Milwaukee won the first three games, Tampa Bay took Game 4 in 12 innings, and the Brewers closed the series 4–1 in Game 5. Jacob Misiorowski threw 5⅔ scoreless innings in the clincher. Rookie Cooper Pratt recorded six consecutive World Series hits, while Jackson Chourio collected 11 hits across the five games. The result was decisive. It was also fully consistent with Milwaukee having had a 12.8% chance at the start: unlikely outcomes still happen.
Did BBMI beat the betting market?
For most teams, BBMI’s title probabilities were fairly close to the pre-playoff DraftKings market after removing the sportsbook margin. Milwaukee was nearly identical: 12.8% for BBMI versus 12.9% for the market. The biggest differences were Los Angeles (BBMI 5.5 percentage points lower), Tampa Bay (5.5 higher) and Houston (4.9 higher). The biggest disagreement went BBMI’s way: Los Angeles, which the market liked more, was swept in the NLCS. BBMI’s higher assessment of Tampa Bay also looked good when the Rays won the pennant. Houston went the other way, losing immediately despite BBMI’s greater confidence. The market prices were reported on September 27, a day before the selected BBMI snapshot, so this is a useful comparison, not a perfectly simultaneous one.
DraftKings World Series prices as published September 27. A price of +600 pays $600 profit on a $100 bet, which implies a 14.3% chance before the sportsbook’s margin. The 12 implied chances add to 110.8%, so each was divided by 1.108 to give the no-vig market figure. Diff is BBMI minus market, in percentage points. The dashed line marks 8.3%, every club’s title chance if all 12 were equal.
We can score the title probabilities, rather than simply counting correct picks. The Brier score measures the squared difference between each team’s predicted championship probability and what happened (1 for the champion, 0 for every other team), summed across all 12 clubs. Lower is better; a perfect forecast scores 0. Giving all 12 teams an equal 1-in-12 chance would score 0.917. BBMI scored 0.874, compared with 0.887 for the margin-adjusted DraftKings probabilities. BBMI did slightly better on this single championship outcome. Its lower Dodgers probability alone improved its score relative to the market by about 0.030, more than the total BBMI advantage of about 0.013. Other differences, particularly its higher Astros probability, offset some of that gain. This is a result worth recording, not proof of a lasting edge over the market.
For each club, the gap between its forecast title chance and the outcome (1 for Milwaukee, 0 for the other 11), squared, then added across all 12. BBMI’s 0.874 and the market’s 0.887 differ by 0.013, drawn to the same scale as the 0.917 an equal-chance guess would score.
What this postseason tells us (and what it doesn’t)
Here is the fair scorecard. BBMI correctly ranked the eventual AL champion as its top pennant contender and favored all four bye teams to reach the LCS; all four did. It missed the NL pennant winner and assigned Milwaukee a 12.8% title chance, close to the market’s estimate. On the specific question of who would win the World Series, BBMI’s probability score slightly beat the market snapshot. Those are encouraging results, not a claim of perfection.
Our standard is simple: publish the probability before the game, leave it on the record, and grade the result. The frozen September 28 board appears in this article, while the live Bracket Pulse now displays the completed postseason. For the larger sample of logged results, see the MLB Model Performance page. We judge prediction accuracy from the complete record, not just one October.
How the board works
Bracket Pulse simulates the postseason 10,000 times on each update. Each game’s win probability comes from BBMI’s plate-appearance simulation of the two clubs’ lineups and starting pitchers, calibrated against regular-season results, and each series follows MLB’s format. The game probabilities behind this board were built from inputs through September 27, the last day of the regular season.
This article uses the board published at 8:15 p.m. Central on September 28. Several pregame reruns on September 29 produced slightly different estimates: Milwaukee ranged from 12.0% to 12.8%, Los Angeles from 24.0% to 25.8%, and Tampa Bay from 14.8% to 16.3%. All eight runs before the first pitch used the identical game-probability table, verified by the same SHA-256 hash, with zero fallbacks and no games played between runs. The differences are Monte Carlo simulation noise, not changes in the underlying forecasts.
Where two probabilities are multiplied above, the events cannot affect each other: the four quarters of the bracket do not meet before the LCS, and the two leagues do not meet before the World Series.
- BBMI odds: Bracket Pulse, as published September 28, 2026, 8:15 p.m. Central, from the site’s published data file.
- BBMI series previews and reviews: Wild Card preview, Wild Card review, Division Series review, World Series update.
- Market odds: Sports Illustrated, DraftKings World Series odds, September 27.
- Game reports: NLCS Game 4, ALCS Game 6, World Series Game 5 (Associated Press).
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This is the “we show our work” side. The Prediction Record is the other half — every call locked before the game and graded in public.