Finally, my last post on the four statistics that I studied on the Twins’ 2009 season to see how good they were at moving runners around the bases (which I call advanced bases percentage). I’ve mentioned several times how my friend Steven didn’t completely agree with my methods, but this one is about as close as I think I’ll ever get to satisfying him without changing my data. I said before that this one is similar to slugging percentage, and now I’ll explain why.
I’m sure you already know this, but I’m going to reiterate it anyway. Slugging percentage is a player’s total bases divided by his at-bats, so a single is one base, double is two, triple is three, and home run is four. So yes, a hitter with a bunch of singles could match a hitter that only gets an occasional home run, but the batting averages would be much different. This last statistic is very similar. I decided to measure the number of bases that a runner advanced during each hitter’s plate appearance. Steven’s biggest complaint was that I was crediting hitters if they advanced a runner even if they made an out, and this stat partially addresses that problem. A hitter could have a respectable average if he made a “productive” out all the time, but the hitters that could consistently advance a runner more than one base (almost always possible only by getting a hit) would rate better. Here’s what I found:
What does this mean? In the case of Joe Mauer (who is once again the leader), whenever he hit with a runner on base, he moved that runner an average of .676 total bases. If it was two runners on base, then each runner advanced an average of .676/2 = .388 bases* .676 bases as well. I was a bit surprised that Orlando Cabrera rated so high, but I’ll address that in a second. I was also interested that Jose Morales had such a poor average, but I wasn’t surprised considering how low his slugging percentage (.361) and isolated power (.050) was last year, even despite his high batting average (.311).
* Stupid error I made last night. If there’s a runner on 1st base and the batter hits a single, which advances the runner to 3rd, the hitter gets credit for 2 bases advanced. That makes a bases advanced percentage of 2.000 (yes, that’s higher than 100%, but just bear with me here). Now if there’s runners on 1st and 2nd and the hitter walks, then he also gets credit for 2 bases advanced. However, this time the bases advanced percentage is only 2/2=1.000 bases advanced percentage, because he averaged one advanced base per baserunner. This should clear up the error I made earlier.
Now, what existing statistics best predicted a hitter’s advanced base percentage?
Not surprisingly, three statistics that dealt with runners on base during a hitter’s plate appearance best correlated with the number of bases those runners advanced. A hitter’s OPS with runners on base best predicted this, and that .894661 was also the highest correlation I got for any two statistics. This is also partially why Orlando Cabrera had such a high rating, because his AVG/OBP/SLG line with runners on base of .314/.338/.415 was better than his overall line of .284/.316/.389…
…although when there was a runner on 1st base, it doesn’t hurt that O-Cab averaged nearly a base advanced per runner (41/46, or .891 bases per runner on 1st base), which also was his most common situation with a runner on base (picture can be expanded by clicking on it). This also explains why I ranked Denard Span over Jason Kubel, because his average was .00034 points higher.
I have a week-long break from school, so I’m considering doing this whole thing over again, but this time I’ll take Steven’s suggestion by no longer rewarding a hitter if he advances a baserunner by making an out. However, I might make exceptions if that out was due to a sacrifice fly. I can’t give a timeline of when you can expect that to be finished, partially because the Twins are finally coming alive during this offseason and because there’s something else that I find to be really cool that I want to take a look at (thanks to some research being done at The Hardball Times).