Thursday, September 30, 2010

It's That Thing that Takes up Time in the Summer

Photo: Morris Kantor via cliff1066™, Flickr Creative Commons

Disclaimer: If you aren't into sports or stats, you should probably just skip this one. I'm actually pretty happy about the results of my messing around with numbers yesterday, so I wanted to share.

I should probably make a minor modification to a claim I've made repeatedly in the past. If you've known me in any way that would qualify you as more than an irregular acquaintance (and reading this blog gives you more insight into my being than most people who know me in person), then you know I hate baseball. Part of this comes from an unpleasant Little League season in middle school, but the main of it comes from the pace. I'm the type who needs to be able to give over my full attention to something to truly love it and, basically, if I don't truly love it, I'm at least mildly annoyed by the thing. That's been my stance with baseball for most of my life.

Except that I've actually been watching some of the games during the last quarter of the current season. The Braves are associated with some positive feelings from my childhood, so there has always been a bit of sentimental attachment there despite my negative opinion of the sport. Also, because I like stats and play fantasy baseball, I've been keeping track of the team in the sporting news for about eight years now. This year, however, maybe because of it being Bobby Cox's final year, or maybe because the Braves were suddenly good again after years of futility since ending their record streak of division championships, I've suddenly tuned in frequently to the games on TV. I've even enjoyed a few of them, although I don't think I'll ever be passionate about baseball. It's still too slow with too much downtime for me to stay fully involved. I usually spend most of the time I'm watching checking my e-mail or playing solitaire on my phone, and I don't have the time to spend watching every game of the season like I'd need to do to become fully involved anyway. The fact remains that I no longer hate baseball. It still ranks below football, rugby, hockey and basketball on my list of sports I'll actually watch, but it does rank slightly higher than soccer, and I actually enjoyed watching the World Cup games this summer.

Anyway, after watching a game where one team left a lot of people stranded on base and lost despite getting significantly more hits than the other team, I started wondering how much a team's offensive efficiency (how many runs they make per hit) correlates with their success as a team. I actually assumed that there would be very little difference in the actual run per hit ratios among teams and that the difference would actually just be the sheer number of hits. It turns out that I was wrong. There was a nearly twenty percent difference between the Tampa Bay Rays at 60.12 percent efficiency and Seattle at 40.63 percent efficiency. I thought 20 percent was a pretty significant variation and it wasn't like those two were outliers. There was a fairly steady slope to that graph.

Now, I don't know exactly how to measure the exact correlation between scoring efficiency and things like winning percentage, but I do know how to look at the graph Excel made for me and recognize that there is correlation, although obviously not a perfect one. Also, I ran the numbers and even with the strangeness of Arizona (21 spot difference between efficiency rank and winning percentage ranking), San Francisco (14 spot difference) and Toronto (10 spot difference), there is only an average 4.73 spot difference between a team's efficiency ranking and their actual win-loss ranking. In fact, eight teams are either exactly the same in the two rankings or just one spot different.

What I can't figure out, exactly, is why this happens. The two teams who are much lower on the winning percentage rankings than their efficiency would suggest are power-hitting teams. Toronto and Arizona are number 1 and 6 by home runs respectively. They just don't get many hits, or wins. San Francisco was the other weird team, but in the opposite direction. They're a successful team this year, but they don't have a very good efficiency and are only average in their hit total. Obviously, they have better-than-average pitching. Those outliers don't explain the other teams, however and I didn't have the time or skills to try and parse out any tendencies related to efficiency. I would imagine, however, that home runs do correlate pretty closely to efficiency.

What I'd like to do next is, one, read a statistics textbook to be able to process the data better and, two, look at some other ways this statistic fits in. For example, I'd like to look to see if there's any connection to efficiency with teams over time, or, if I really got ambitious, if it followed specific managers or batting coaches over time.

Also, I make no claims that this is a unique statistic. I'm sure some of those specialty sports statisticians already track this and work with it, but it's not a part of the stats on and I apparently had enough free time yesterday to do a little copy and pasting and Excel magic.

1 comment:

Julie said...

Congratulations on your Excel wizardry. I have the warm fuzzies for the Braves, too, but I haven't tuned it yet this season. Since my general feeling about sports is "meh" and I'm encouraged/forced to watch so much football, I let the general interest sports fall to the wayside.