Where did that 62% number come from? Somebody’s computer model? Vegas? Thin air. (There’s another expression for that one.)
Rough probabilities would be calculated as the Dodgers needing 2 favorable outcomes in 2 events (or trials). Assigning equal probabilities to either a favorable or unfavorable outcome one would reckon that the Dodgers have about a one in four chance right now:
1/2 x 1/2 = 1/4 = 0.25 or 25%.
The remaining probability, 1 - .25 = 75% belongs to the Astros.
Sophisticated computer models may model starting pitching, lefty-righty match ups, home field advantages, etc., but the outcomes over the long run tend to run about 50-50 on each game.
By the way, a small pedantic note on the difference between odds and probabilities, from a frequentist perspective. Probabilities are the ratio of favorable outcomes, to all outcomes. What I cited above are probabilities. Odds are a betting proposition. Odds give the ratios of two sides of a wager. If you believe that the probability that the Astros will win is 75%, then fairs odds would be 3:1. A wager of $3.00 dollars on the Astros wins $1.00, a wager of $1.00 on the Dodgers wins $3.00. The person betting on the Astros would win $1.00 three out of four times, and lose $3.00 once out of four, and on average he would be even. That’s a fair bet. The person betting on the Dodgers is the counterparty to the above wagers, and would come even in the long run, also. In a fair bet, on average, no money changes hands.
Differences in the perception of the odds is what makes wagering popular, often those differences are driven by emotional rather than rational choices. “Differences of opinion is why there are horse races.” I like to wager, when I perceive that the odds are in my favor. Especially with Yankees fans.
I’d jump on the Astros at 19-31 odds (38-62), winning $19, three times and losing $31, once in four trials or:
($19 x 3 - $31) = $26/4 = $6.50
An expectation value of $6.50 on a $31 dollar wager.
Teams that have taken a 3-2 edge in the World Series have gone on to win the title 67.7 percent of the time, according to whowins.com. Because the Dodgers have home-field advantage, a Game 5 win would increase their odds to 75.0 percent. If Houston wins Game 5, its odds are set at 61.8 percent for the remainder of the series.
Astros favored to take Game 6 by Vegas (and others) but just barely. If they lose Game 6 they will not be favored to win the Series. They MUST win Game 6.
http://www.vegasinsider.com/mlb/odds/las-vegas/