In 2009, the Yankees won 15 games in their last at bat. That’s a lot of games that could’ve gone either way, but because of a few things, they went the Yankees’ way. A lot of it is the fact that the 2009 Yankees were an incredible hitting team and that allowed them to rarely feel like they were completely out of the game. Of course, luck was also a factor. When the game is so close that it must go down to the last at bat or extra innings, a team will almost always be lucky to win. How lucky were the 2009 Yankees when it came to walking off in 2010?
HUGE DISCLAIMER: I DID NOT DO VERY WELL IN STATS 101 MY SENIOR YEAR OF COLLEGE SO SOME OF THIS MATH MAY BE A LITTLE FUZZY. IF ANYONE OUT THERE WANTS/NEEDS TO CORRECT MY MATH IN THE COMMENTS, PLEASE DO SO.
To try and figure this out, I went to the Yankees’ pages on Baseball Reference and looked at the last ten years results data. The Yankees had the following number(s) of walk off wins in the given years:
That’s a total of 71 walk off wins in the last ten years, so the average is 7.1 walk off wins per year. To see if the Yankees got a little lucky in 2009, I also calculated the standard deviation of this set of data. That came out to be about 3.4. According to the Empirical Rule, 99.7% of data lies within 3 standard deviations of the mean (average).
So, to see years in which the Yankees got lucky (or unlucky) let’s multiply our SD, 3.4, by three (10.2) and add it to our mean, 7.1.
7.1 + (3.4*3)= 17.30
What this tells us is that anything higher than 17.3 walk off wins would be a ridiculous outlier. It would seem, then, that the Yankees’ 15 walk off wins, no matter how gaudy and outlandish looking it was, were not too much of a statistical outlier.
Still, this sample is still relatively small, so I’m not sure exactly how reliable it is. Not only am I only using one team and not comparing these numbers to the broader league average, but the team has changed so much since 2000 that the teams are completely incomparable.
Going forward, this half-assed study doesn’t have any real predictive value, but it was fun to just crunch some numbers and remind myself of how awesome the Yankees were in walk-off situations last season. So, I leave you with a video of the two walk offs for which I was in attendance: