Tuesday, November 3, 2009

Quick Post on Curious Poll Results

I was jetting around the internet this morning checking up on the latest sports news and came across a poll at CBS Sports that asks the following question:

How will the World Series End?

A. Yankees in 6 (46%)

B. Yankees in 7 (11%)

C. Phillies in 7 (44%)

The thing that really interested me here was the breakdowns of voting. It was really intriguing to me that so few people thought the Yankees would win in 7 (I personally voted for Yankees in 6 with no allegience to either team).

At first glance, we might think, "Why do so many people think that if the Phillies win tomorrow night, they have a 4x larger chance of winning the whole thing than the Yankees?" But let's break this down a little differently and rephrase:

Who will win the World Series?

A. Yankees (57%)

B. Phillies (44%)

I know those don't add up to 100%, but it's just a rounding error. Anyway, it looks like the majority thinks the Yankees will win the World Series. That's expected, given where it's at right now. The problem with our first glance is this: we're not conditioning the Yankees win on having to play a Game 7, while the Phillies MUST play Game 7 to win.

What the original poll is telling us is not that people think the Phillies have 4x the odds of winning that the Yankees do, given there's a Game 7. If we re-run the poll after tomorrow night's game, assuming the Phillies won, we'd probably see something more like the second poll. Those that think the Yankees will win in 6 games will just vote for the Yankees in Game 7 (mostly). Why is this interesting?

Well, it relates back to the way that the Olympic voting took place and how the votes that are split between two choices become skewed when there is multi-part voting. Apparently, many voters had Chicago and Rio as their top 2 choices, but that actually was bad for Chicago. JC Bradbury has an interesting post on it here.

Anyway, nothing groundbreaking in my post. It's a pretty well-understood phenomenon. I hadn't posted anything for a while, and needed a brain dump. I just thought it was interesting, given my first impressions of the poll.

On another note, I'm fiddling with positional adjustments for the HOF Batters to see if I can improve my prediction model from before. I'm also working on an article discussing the optimal auction structure for fantasy baseball leauges. Those should be up here shortly.

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