|The Curse of the Billy Goat
(or why the Red Sox won't. Or the Rangers or Nationals or Giants or Dodgers or Blue Jays or Orioles or Indians or Mets for that matter. Insert any team name into the title, and this post still makes sense).*
At the trade deadline I had a post showing what the impact of a adding a player to a team would be on its likelihood to make the playoffs and/or win it all. There were two separate points. One was that a single player, no matter how good, will not make a large difference in one team’s win totals over two months. The second, more interesting point, was to show how little of an edge a great team has over a good team in a playoff series.
I have updated the spreadsheet I used to calculate the odds in that post to show the actual season end records. Here are the results:
A quick reminder how I arrived at these numbers. My model calculates a team's probability of winning a game against an opponent as 50% + the difference in their winning percentages. And then basic math figures out all the permutations to come up with these totals. The original post shows more details.
But looking at the Cubs, we see they have a 60% chance of beating the Giants (or the Mets) in a single game, which works out to a 68% chance of winning the LDS. Their probability of beating the Nationals in the LCS are 61% (and the Nats have a 55% probability of beating LAD to get there), and a 66% probability of beating the Dodgers (who have a 45% chance of getting there). Multiplying all the odds together gives them a 43% chance of getting to the World Series. Once there, the odds of them beating their opponent range from 59% (vs the Rangers) to as high as 68% (vs one of the bird teams). Again taking into account who they may play and multiplying that out by the 43% probability that they'll even make it that far, we end with the 26.8% that shows up on the chart above.
Now, my model does not take into account who the home teams are. League wide home teams win 53% of their games. So when two teams with identical records match up, instead of each team having a 50% probability of winning, a slightly more accurate model would show the home team with a 53% chance of winning. And taking it further we could look at individual team’s home and away records. For example, the Mets won 44 games at home this year, while the Giants only won 42 on the road. Taking those specific numbers into account would show that the Mets would have a 52% probability of winning their wildcard game, instead of the 50% that my model shows when using each team’s overall 87-75 records. Meh…. Over 162 games this factor may make a small difference (actually, if you’ve been reading, you know that it does! When two even teams play, the home team has a 53% probability of winning.) But in a one game winner take all, or even a best of 7 series, it’s not going to tilt the odds so much that you can declare a team “heavily favored because they got home field”.
The bottom line is that even though a lot is made of home field advantage and having the crowd on your side, these are all just stories for the TV pregame show and don’t really make much of an impact on the playing field.
My simplistic model doesn’t take that into account. Or who’s hot. Or who has even year jinxes working in their favor. But what it does do, is put some numbers behind the whole “the playoffs are a crapshoot” idea. The playoffs are not a crapshoot. A very good team has a better chance to win than one who barely sneaked (snuck?) into the postseason. But it does show that the odds of the best team winning are still low. So, if the Cubs don't win, it won't be a huge upset.... there's almost a 75% chance that they won't win.
* (you just can't insert ALL the team names into the title. Then it won't make sense)