Wednesday, August 06, 2008

What about walk off losses?

In my previous post, I examined the effect of walk off wins on a team's performance the next day. I found that the winning percentage in games immediately after the walk offs was almost exactly the same it would be if we assumed no carryover effect from the day before. Thus, the theory that a sudden victory creates a psychological lift which leads to success in the following games seems to be, in general, untrue.

Eddie at Tigers Thoughts wanted me to do the same analysis for walk off losses. It has been said the effect of a walk loss is more demoralizing than a walk off win is uplifting. I'll test that theory using the same method as I did for walk off wins. I used the same 1995-2007 data set (excluding 1999) with 2,473 walk offs. It turns out that teams won just 46% of the games immediately following walk off losses but we can't stop there.

As with walk off wins, there are there are two factors to consider. First, walk off losses happen on the road and are followed by road games 86% of the time. Since teams win just 46.1% of their road games, you would expect them to have a low winning percentage in games after sudden losses even without a carryover effect. Also, teams with low winning percentages tend to have more walk off losses. For both of these reasons, one would expect a win in the next game after a walk off loss less than 50% of the time even if walk off losses had no influence.

I calculated the expected winning percentage in games after sudden losses the same way as I did in my previous post. That is, I first computed the winning percentage of the specific team for that year and site. For example, the 2007 Twins won 46.9% of their road games. Thus, they would have a probability of .469 of winning a home game the day after a walk off assuming no carryover effect. I did this for each of the 2,473 walk offs and then calculated the average probability to be .457. This means, that assuming no carry over effect, we would expect 45.7% of the games after walk offs to have resulted in wins.

Since the expected winning percentage (45.7%) for games after walk offs was almost the same as the actual winning percentage (46.0%), I can conclude that, in general, a walk off loss has no affect on the result of the following game. So, based on this analysis, it appears that the walk off losses are not as demoralizing as some think....let's hope that rings true for Wednesday's game. Ouch.

The information used here was obtained free of charge from and is copyrighted by
Retrosheet. Interested parties may contact Retrosheet at "www.retrosheet.org"

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