It's how the climate -- expected to be in the 40s and raining all weekend -- will affect the outcome.
The forecast for Saturday in Chicago is a temperature in the mid-40s with a 60 percent chance of rain. Sunday's forecast is similar.
"We are not looking at the weather being a factor until something is laid in our laps," White Sox pitching coach Don Cooper said. "We are ready to play and we are going to go with that until somebody changes it. I don't think it will affect us unless it is crazy, and I don't think we will be playing in crazy weather."
Want crazy? The forecast in Houston for the same two days is sunny with a temperature in the low 80s. There is no chance for precipitation in the Bayou City for the weekend, but it would not matter anyway.
The Astros have a retractable roof at Minute Maid Park.
"[The weather] is a factor here for the simple fact that we have not played in it since April," Astros pitching coach Jim Hickey said. "We play indoors and in climate control, but the only thing that worries me is the wetness and the mound becoming slippery."
Visitors beware, but the climate also has the potential to lessen the home-field advantage for Chicago during the first two games of the series. The White Sox rely on bunting, particularly at the top of the lineup with Scott Podsednik and Tadahito Iguchi, and the rain could make handling a bat a challenge. A muddy infield might also affect Chicago's aggressiveness on the base paths.
Additionally, the bitter cold could also affect the players' hands on offense and defense -- for both teams. Staying warm, in every sense of the word, will be at a premium.
"You have to consider the elements when you think about bunting or stealing a base," Podsednik said. "But you have to understand that they will be playing under the same conditions. I think it will be a game-time decision as to how we go about bunting and running and doing those kinds of things."
How the climate will affect Houston starter Roger Clemens and Chicago starter Jose Contreras, who each throw a split-finger fastball among their assortment of pitches, remains to be seen. For the pitchers, having a good grip will be as important as having a good arm.
"It won't be a problem," Contreras said. "The last game, it was raining the entire game and it didn't affect me. Why should it here?"
He's right. In Game 5 of the American League Championship Series, Contreras pitched a complete game to clinch the series in Anaheim in the rain. However, it was not 40 degrees.
"The actual temperature is not that big of a concern," Hickey said. "It might affect hitters more than pitchers, because pitchers are constantly moving."
In the 1997 World Series, the Florida Marlins and the Cleveland Indians faced a similar challenge. For Games 1 and 2 in Florida, the temperature was 76 and 77 degrees, respectively. For the games in Cleveland, the temperature dipped into the 30s and 40s, going as low as 15 degrees during Game 4, a record low for a World Series game.
"[Weather is] one of the smallest factors I'm really looking at," Cooper said. "The bigger one is our inactivity from our relievers, although we have done what we can to get them ready. Our starters are ready to go. Here we go."
Come rain or shine.
Jesse Sanchez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.