By Steve Silver, FanGraphs.com/LRS
Monday, May 14^th, 2012

Hello, LRS sports fans!  My name is Steve Silver.  I am here to bring you a new feature to Fangraphs.com, and that is LRS’s version of stats corner.  Every week, we will be evaluating players using three metrics.  Since this is the first edition, we are going to introduce the metrics before showing the Top and Bottom 20 lists for each.

wOBA (Definition courtesy of Yahoo! Sports)

First up is wOBA, the stat that is used to measure the next two stats we will look at.  It’s called wOBA because the number is scaled to look like OBP – which is also sometimes called OBA – not because it actually is a variant of OBP.  wOBA is scaled to OBP for two reasons.  First, we’re all familiar enough with OBP to be able to eyeball and tell a good percentage from a bad one.  Second, it means that league OBP is defined to equal league wOBA.  wOBA is useful when you just want to know how a batter did at the plate, regardless of who was on base or what the score was at the time.

wOBA is a linear weighted number.  Linear weights attempt to properly value a player’s contributions at the plate by weighting each possible outcome (walk, home run, single, double, etc.) with regard to the number of additional runs that player’s team can expect to score as a result.  For example, home runs have a run value well over one because runners can be on base, and singles have a value slightly higher than walks because singles frequently move baserunners from first to third or from second to home.

wOBA is nice because it combines the insights of OBP (how good a batter is at getting on base) with the insights of SLG (how good a batter is at hitting for power), but it also properly weights each outcome, and is therefore superior to non-weighted stats like OPS and OPS+.  Simply put, it’s a better method to see who’s the best hitter in the league.  Now, here are the top 20 hitters in the LRS using wOBA:

As you can see, there is a bit of a problem with small sample sizes here.  For example, the top three players in terms of wOBA have a combined 6 at bats.  This is going to be taken care of with the next few stats we look at.  The same problem appears when you look at the bottom-feeders in the LRS:

The bottom 16 hitters have a wOBA of 0, meaning they haven’t gotten a hit, walk, or a HBP in their at bats.  Though this is a little deceiving because the highest number of at bats any of these guys have received is 7.

wRC (Definition courtesy of Sabermetric Library)

Runs Created (RC) was Bill James’s first attempt to quantify a player’s total offensive value and measure it by runs.  This way, instead of looking at a player’s line and listing out all the details (e.g. 23 2B, 15 HR, 55 BB, 110 K, 19 SB, 5 CS), you could synthesize all the information into one metric and say, “Player X was worth 24 runs to his team last year.”  While the idea was sound, James’s formula has since been superseded by Weighted Runs Created (wRC).  Developed by Tangotiger and displayed at FanGraphs, wRC still measures how many total runs a player was worth over a time period, but is based off of wOBA instead of Bill James’s formulas.

Here is the top 20:

As you can see, this helps eliminates the problem of high wOBAs with few plate appearances.  wRC rewards players for maintaining high wOBA with increased PAs.  Tomiji Watanabe, the centerfielder from the Kure Arsenal, has been able to keep a wOBA of .677 over 27 plate appearances.  That means he has created 11.586 runs for Kure.  That is nearly two more runs than second-ranked José Escalante from the Lupin Cliff Hangers.  Now, let’s take a look at the bottom-feeders:

We still have some players with a low number of plate appearances, but this gives us a good idea of who is really hurting the team.  A few of the guys are on the list despite plate appearances in the 20s.  Included is Tamuramaro Gato from the Niihama-shi Ghosts.  He has cost his team approximately 1.643 runs.

wRAA (Definition courtesy of Sabermetric Library)

The final stat we will be looking at today is Weighted Runs Above Average (wRAA).  wRAA is similar to wRC in that both statistics summarize a player’s total offensive output into one stat and express their value in runs.  The key difference between wRC and wRAA is that, while wRC measures total offensive contributions, wRAA provides more context.  wRAA specifically calculates the number of runs a player contributes to their team above what an average player would contribute.  This makes it easy to see how above or below average a player is, which can be tough to visualize with wRC.  Here are the best:

Again, it is Watanable from Kure by a wide margin.  If Kure replaced him with an “average player”, they would be costing themselves almost eight and a half runs.  Now, lets take a look at the bottom 20:

Again, it is Gato leading the pack, but something is telling me he doesn’t want to be on the top of this list.  If the Ghosts could somehow get an “average player” in place of Gato, they would gain nearly four and a half runs.  Also, an interesting note from this list is that four of the league’s 12 starting catchers are in the bottom 20.  This tells us something about the league’s strength at catcher.