Aluminum Adjustments (Part 2)
When we last parted, fair reader, I was blabbing away with the contention that college pitching statistics could be effectively separated from the effects of defense, parks, and strength of competition. But at least I made it up to you by offering up a Top 25 List. And nothing whips us baseball fans into a lather quite like a list. So today's installment promises more of the same. Only this time, we turn our attention to college hitters.
In analyzing this year's draft-eligible college hitters, we'll begin with the same "scouting" filter applied to the pitchers. This time, the list of hitters was further refined using the metrics explained below.
And, again, this is not a list based on any type of prediction as to how these players will perform at higher levels.
NAME/SCHOOL/POSITION - Pretty much as you'd think.
OPS - A traditional measure of a player's all-around offensive performance.
POWER - Chicks dig the long ball. Here a player's power will be expressed in two ways:
Here's a quick, feeble explanation of linear weights, because we'll talk about them again later on. The role of the hitter is to produce runs. That's their end of the bargain. It is possible to quantify the value of each offensive event, (walk, single, double, etc...), based on how it contributes (or hampers) run scoring. Using these values, you can judge a hitter's overall offensive value by taking the value of each offensive event and multiplying it by the rate at which he gets them. Is that clear as mud? Sorry. Anyways, linear weights power measures only those events (doubles, triples, home runs) that are a reflection of a hitter's power.
SPEED - Speed is a Tool that doesn't seem to translate well into traditional offensive statistics. Here, we'll use a player's Speed Score, a metric pioneered by Bill James. When determining a player's Speed Score, we'll look at a function of his stolen bases, stolen base attempts, triples, and the percentage of times scored once on base.
DISCIPLINE - Earlier this year, on another popular baseball website, a leading sabermetrician with connections to a major league team offered the following (paraphrased) opinion: "one key to a good draft is selecting players with excellent plate discipline at the expense of hitters with gaudy, yet possibly illusory, power numbers." This is incredibly valuable insight. For us baseball geeks, it's as if Warren Buffett dropped into a Yahoo Finance chat room and said "Hello. If you're looking to invest in the stock market right now, I recommend everyone invest disproportionately in manufactured housing sector stocks with P/E ratios under 12.5 and R&D budgets that represent between 5-8% of their previous year's revenues. Have a nice day." So, we're going to take a look at a hitter's plate discipline, using these metrics:
wOBA - This is where it gets good. OPS is a fine statistic. It's quick (OBP+SLG), and everyone can quickly digest the fact that 1.000 = great. But it's not exactly what we want. Because all OPS really gives you, essentially, is the ability to pick up a player's wallet and see how fat it is. Bigger is better, that's for sure. But if you really want to be able to get a clear picture of how much a player is worth, you need to be able to open up the wallet and see exactly how many, and of what denomination, bills he has inside. And that's where Andy Dolphin, Mitchel Lichtman, and Tom Tango come in. In their recent book (which you should buy), they introduce what they call wOBA. Here's what it is: wOBA is a linear-weights (remember these?) based formula scaled to map with OBP. So, .300 = bad, .400 = good, .500 = great. It's basically a batter's run value per plate appearance, scaled in a way that makes it more user-friendly (when you read wOBA, think OBP).
AwOBA - Hitters are ranked by this metric. It is wOBA, adjusted for park and strength of schedule. Building again on the work of Boyd Nation, using his Division I park factors, I have taken each hitter's wOBA and first adjusted for the parks in which they played. Next, I took the now park-adjusted wOBA and isolated that from the strength of a player's schedule, averaging the ISR -- another Boyd stat -- of the opponent's of each player.
Now then. Let's take a look at the Top 25 offensive seasons registered by this year's draft-eligible college hitters, as sorted by AwOBA.
THANKS: Once again, these articles, and the research that underlies them, simply would not have been possible were it not for a few extremely smart people I have had the pleasure of getting to know in a non-creepy internet way over the past few months. First, Tom Tango offered insight, wisdom, and advice every step of the way. He is a brilliant guy, and the fan in me can only hope that he is on Theo Epstein's speed dial. Craig Burley's previous work in this area helped inspire me to undertake this effort in the first place, and his thoughts along the way even helped it all make sense. And finally, of course, I can't even begin to thank Boyd Nation for all of his time and help. Remember, when it comes to college baseball, it's Boyd's World, and we're just living in it.