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Saturday, October 22, 2005
Diamond Mind: Simulating the Series

By Tom Tippett
Special to

Editor's Note: Diamond Mind is devoted to providing realistic, strategy-oriented baseball games for use at home and on the Internet. asked Diamond Mind to simulate the World Series, and here, Tom Tippett describes how it was done. For more information, go to Diamond Mind's Web site:

How It Played Out
Diamond Mind's simulated outcomes for the 2005 World Series:

Astros win, 4-3
Game 1: Astros 3, White Sox 2
Roger Clemens, Dan Wheeler and Brad Lidge made an early three-run homer by Brad Ausmus hold up in a 3-2 win.

Game 2: White Sox 10, Astros 3
Paul Konerko hit a two-run shot off Andy Pettitte in the first and a grand slam off Pettitte in the second to end the suspense early in a 10-3 Chicago victory.

Game 3: White Sox 5, Astros 2
Jon Garland and Roy Oswalt battled to a 2-2 tie through seven before Konerko homered in the eighth and added some insurance with a two-run shot in the ninth in a 5-2 Chicago win.

Game 4: Astros 5, White Sox 4
Houston rallied from a 4-0 deficit to win 5-4 and square the series.

Game 5: White Sox 2, Astros 0
Jose Contreras outdueled Clemens in a 2-0 Chicago win, throwing 133 pitches and coming one batter short of going the distance, with Scott Podsednik stealing three bases and scoring both White Sox runs.

Game 6: Astros 8, White Sox 0
In a reversal of Game 2, Houston staked Pettitte to an early lead and cruised to a 8-0 win to force a seventh game.

Game 7: Astros 4, White Sox 2
Chicago took a 2-0 lead in the fourth on a pair of unearned runs that were plated by a Joe Crede double with two out. In the sixth, Morgan Ensberg cut the lead in half with a solo homer. Houston took the lead for good in the seventh when Orlando Palmeiro pinch-hit for Ausmus and blasted two-run homer. Ensberg added another solo shot in the eighth to make it 4-2, and Lidge closed it out for his third save of the series.

Final batting stats
Final pitching stats
The players were rated to perform based on their 2005 statistics, including left/right splits. When the simulations were run, the final rosters for the World Series had not yet been announced, so we used the 25-man rosters on

All games were simulated with the computer manager handling both teams according to the manager profiles we set up.

For each team, the manager profile included four saved lineups, for left- and right-handed opposing pitchers and for DH and non-DH games. Each of those starting lineups was paired with a depth chart that governs how bench players are to be used, including defensive replacements and platoons.

Both teams were set up with a four-man starting rotation based on recent usage. For Chicago, we went with Contreras-Buehrle-Garland-Garcia. For Houston, it was Clemens-Pettitte-Oswalt-Backe. In both cases, it allowed all starters to work on normal rest. Relievers were assigned to the roles in which they've been used -- closer, setup man, long relief, or mopup duty.

Pitcher fatigue isn't a big issue for this series. Chicago has had enough time off so that all of its pitchers are at full strength. Houston played only one game in the four days leading up to the Series, so we entered the pitch counts for their Game 6 win. But those pitch counts won't have much of an effect because Oswalt wasn't slated to pitch until next Tuesday and the Game 6 relievers only threw a few pitches before getting two days off.

Because there is no way to predict who might or might not get hurt in the course of short series, the DMB injury system was turned off.

The DMB weather system was turned on, so if you check the box scores, you'll see typical October weather for the two cities.

Running the simulations

We simulated the series 100 times, with Houston winning 55. The outcomes were distributed as follows, with a progression from Houston dominance at the top to Chicago dominance at the bottom:

Houston in 4 -- 3%
Houston in 5 -- 19%
Houston in 6 -- 16%
Houston in 7 -- 17%
Chicago in 7 -- 12%
Chicago in 6 -- 16%
Chicago in 5 -- 13%
Chicago in 4 -- 3%

Although a Houston victory in five games was the single most common outcome, we don't believe that it is representative of the matchup. If we had run the simulations 1,000 times instead of 100 times, we're sure that Houston-in-5 would not have been in the top spot.

Houston in seven fits the data much better -- it reflects the fact that Houston won only 55 percent of the time overall, it's the second most common outcome, and it's in the center of the range of the most likely outcomes.

As a result, we chose to provide you with box scores from one series that Houston won in seven games. As it turned out, among all 100 simulations, Houston won Game 1 62 percent of the time and Chicago won Game 2 60 percent of the time, so we chose the first (of two) series that began with this pattern and ended with Houston winning in seven.

Here's one comment about the computer manager's decisions: You'll see that Willie Harris and Geoff Blum were used as pinch-hitters for Chicago in Game 1. That might seem odd given that neither is an especially good hitter. But the computer manager saw how dominant Lidge is against right-handers and thought it would get an edge by sending a lefty to the plate. As it turned out, it worked, as both were able to reach base.