ERA+ (Earned Run Average Plus)

Formula: 100 * league ERA / ERA * Park Factor

Pros:  Allows you to compare pitchers from different eras, teams, and leagues because of its park and league adjustments.  Also shows you whether a pitcher was roughly average, above average, or below average.  Better than using just regular ERA because it provides context.

Cons:  Doesn’t account for things beyond a pitcher’s control, such as bad defense and/or bad luck.  Starters and relievers are lumped together as well, despite relievers having on average a lower ERA than starters.

Examples:

Replacement Level Starter: Guys found in this category are generally career minor leaguers, non-prospects, organization filler, injury replacements, etc.  They’re likely to put up an ERA+ around 80 or so.  They generally have below average stuff, poor command and poor makeup.  A Tim Redding, Jorge DePaula, etc. occupy this level of “pitching.”

Below Average Starter: Generally pitchers with an ERA+ of 90.  Most teams have these guys as their number four or five starters.  They generally possess command of two major league quality pitches with average velocity.  If you want to know what a starter like this looks like, go to any Tampa Bay Devil Rays game that Scott Kazmir isn’t starting.

League Average Starter: This is a pitcher with an ERA+ right around 100.  These are generally number three pitchers – one plus pitch, two average pitches, and average command and makeup.  Think an Esteban Loazia or Livan Hernandez.

Above Average Starter: Pitchers with an ERA+ around 110 can be classified under this category.  These are generally number two or three pitchers – he is likely to have two plus pitches instead of just one, however.  Think of Brad Radke or David Wells.

All Star Starter: Generally a pitcher in this category should be capable of putting up an ERA+ of about 120 in any given year.  He is likely to have two plus pitches as well as plus command and makeup.  They can pass of as an Ace on a contending team, and they may even pass off as a Hall of Famer.  You’re likely to find guys like Andy Pettitte, Barry Zito, and Bartolo Colon here.

Hall of Fame Starter:  These are the guys who can head all time great rotations.  Any year they pitch you’re not surprised to see an ERA+ of 130 or greater, and in their best years they’ll approach 170 and higher.  To be a Hall of Fame starter you generally need two plus-plus pitches, plus command and plus makeup.  The Roger Clemens, Randy Johnsons, and Pedro Martinezes of the world are located here.
 

05.21.2006 NoMaas Stats 101: OPS+

So far we've taken a look at Batting Average, On-Base Percentage, Slugging Percentage, and OPS.  One disadvantage to all of these stats is that they are neither park-adjusted or league-adjusted.  Oftentimes, people overlook that a particular ballpark or league can influence a player's statistics.  For example, if a player's homepark is a hitter's park, his stats are most likely inflated.

Now, we enter the world of adjusted statistics which provide a more accurate means of evaluating a player's performance and comparing him to others.  We begin with OPS+.

OPS+ (On-Base Plus Slugging Plus)

Formula: (OBP / lgOBP * Park Factor + SLG / lgSLG * Park Factor – 1)  * 100

Pros:  Adjusts for ballparks and leagues.  Allows you to compare hitters from different eras, teams, and leagues using a simple formula that captures the majority of what makes a hitter valuable.

Cons:  Doesn’t account for position, so a SS with an OPS+ of 125 would be seen as the equivalent of a 1B with the same.  Players with a low OBP but great SLG tend to be overrated, at least slightly, since they are counted as equal.  Strikeouts and double plays aren’t included, nor is baserunning.

Examples:

Replacement Level: Guys found in this category are generally career minor leaguers, non-prospects, organization filler, injury replacements, etc.  They’re likely to put up an OPS+ around 80 or less.  They strike out often or make weak contact, have bad patience, and little to no power.  The Enrique Wilsons, Bubba Crosbys, and Tony Womacks occupy this level of “hitting.”  They serve no value on offense, and should only be in the majors if they are exceptional baserunners and/or defenders.

Below Average: Generally hitters with an OPS+ of 90.  These guys generally play the 2 positions on the defensive spectrum farthest to the left, catcher and shortstop.  Their problems can range from having mediocre contact rates, below average patience, and middling power.  Benito Santiago, Olrlando Hudson, and Jimmy Rollins are the type of guys you expect to see here.  These guys are valuable as bench players, and if they play an important defensive position well enough are fine as starters as well.

League Average: This is a hitter with an OPS+ right around 100.  These guys are fine as everyday players if they’re a 2B, 3B, or CF.  Any weaknesses they have are made up for with slightly above average skill in another.  Think of Robinson Cano’s rookie season, Chone Figgins (this does not include baserunning obviously), and Torii Hunter.

Above Average: Hitters with an OPS+ of 110 to around 120.  This is generally the minimum you want from your power positions: 1B, LF, and RF.  Jeff Conine would represent the minimum for this category, while Ichrio! is as good as it gets.

All Star: A hitter in this category should be capable of putting up an OPS+ greater than 120 in any given year.  He should make about average contact and have good patience and very good power.   An everyday DH should be able to put up an OPS+ of at least 120 every year.   Think Derek Jeter (the fact that he’s a SS makes his offense so valuable), Hideki Matsui, and David Wright up to this point.

Superstar:  These are the guys who can, in any given year, put up at least an OPS+ of 130 and generally will be closer to 140.  If they strikeout a lot it’s only because they’re constantly working the count for their pitch to hit.  They have very good patience and at least very good power. Albert Pujols, Barry Bonds, Jason Giambi, Manny Ramirez, David Ortiz, Alex Rodriguez, Vladimir Guerrero.  You know these guys when you see them.  They’re the guys that will punish your pitching staffs.  Just pray you’re not facing them with the game on the line.
 

05.08.2006 NoMaas Stats 101: OPS

On-Base Plus Slugging Percentage (Known as OPS):

Formula: OBP + SLG ~ description not necessary. See previous NoMaas Stats 101 installments for the individual formulas for each individual component statistic.

Pros: Provides a comprehensive overview of player performance, all wrapped up into one number. Very easy to understand, because it simply acts as a combination of two fairly common stats. While you might not hear the average fan talk about OPS in the bleachers of Yankee Stadium, it is very commonly referenced on internet baseball forums and as such, is generally well-regarded in the sabermetric community.  OPS is also slowly making its way into the mainstream media as you can find this metric on the ESPN stat pages.

OPS serves as one of the most "accurate" of the unadjusted measures (AVG, OBP, SLG, etc.) when trying to evaluate player performance because it combines two good statistics into one better statistic.

In 2005, the American League average OPS was .754 (.330 OBP + .424 SLG).  Alex Rodriguez had an OPS of 1.031 (.421 OBP + .610 SLG) in 2005.  This led the league.  In comparison, Tony Womack had an OPS of .556 (.276 OBP + .280 SLG).

Cons: Because OPS contains OBP and SLG, by definition, all of the problems that affect both OBP and SLG will affect OPS. As with other multi-component statistics, it illustrates the overall performance impact that a batter contributes, but it lacks the ability to specify where the impact is derived from.

For instance, a player that is a pure slugger but lacks the discipline to have a high on-base percentage (i.e. .300 OBP, .600 SLG) will have the same .900 OPS as a player that is a bit more well rounded (i.e. .400 OBP, .500 SLG). Obviously, these players have different "skill" sets, yet make the same overall performance contribution. In this sense, OPS is not very descriptive..

Comments: NoMaas, and many other baseball websites, like to use OPS as a measurement of player performance. In general, the descriptive deficiencies of OPS mentioned in the "Cons" section are overcome by the fact that OPS does provide an accurate means of looking at overall player value.
 

04.17.2006 NoMaas Stats 101: Slugging Percentage

Slugging Percentage (Known as SLG...):

Formula: (1*1B + 2*2B + 3*3B + 4*HR) / (AB) ~ the quantity one times the number of singles hit by a batter plus two times the number of doubles plus 3 times the number of triples plus four tmes the number of home runs divided by total at bats.

Alternate Formula: TB / AB ~ the number of total bases accumulated by the batter divided by the number of at-bats.  For example, if a player has 1 AB and hits a HR, his slugging percentage would be 4.000.  A home run consists of 4 total bases.  Four total bases divided by 1 AB equals 4.000.

If a player has 3 ABs and goes 2 for 3 with a HR and 2B, his slugging percentage would be 2.000 (6 total bases divided by 3 ABs).

Babe Ruth has the highest career slugging percentage at .690.  That means Babe Ruth averaged 0.69 total bases per AB.

Pros: Provides a simple, easy-to-understand measure of a batter's power potential by evaluating the number of each kind of hit a batter manages to get and assigning a value corresponding to the number of bases gained for each of them and then dividing by the number of at-bats.  Generally, the higher the SLG percentage is, the more power a player has shown.  Common enough so that pretty much anybody that understands batting average will comprehend it. Can be used in combination with other statistics to arrive at more complex statistics. Commonly understood as a fairly important statistic both in and out of the sabermetric community.

Cons: Subject to the same random influences as batting average.  Assigns an arbitrary number of bases to each type of hit, even though the true marginal value of a triple over a double is not as great as the marginal value of a double over a single (proven by somewhat convoluted statistical tests).

Comments: While not completely descriptive of player ability, it is still a decent enough measure of performance and is common enough that most fans will understand the basics of it. The principles of assigning weights to events involved in deriving slugging percentage provides a more methodical means of arriving at a measure of performance, although as mentioned earlier, the weights are assigned without respect to any kind of statistical evaluation. Nevertheless, the principles of assigning weights will play an even more important role when NoMaas delves into more complicated measures like Davenport's EqA and Linear Weights.
 

04.06.2006 NoMaas Stats 101: On-Base Percentage

On-Base-Percentage (Known as: OBP, OBA, BP...):

Formula: (H + BB + HBP)/(AB + BB + HBP + SF) ~ The quantity of hits plus walks plus times hit by pitch divided by the quantity at-bats plus walks plus times hit by pitch plus sacrifice flies.

Pros: Provides a quick, comprehensive evaluation of the number of times a player was able to get on base. Fairly common enough so that many, if not most fans and players will know what it is (with a higher likelihood of good interpretation). Can be used in combination with other statistics to arrive at more complex statistcs. Widely heralded as one of the most important measures of offense.

Cons: Still subject to the same problems as batting average with regards to hits, but is more likely to be representative of a players true ability.

Comments: By far and away one of the most important measures in the game, because of ease of understanding, high level of predictive value for scoring runs, and easy accessibility on the internet. OBP is based less on the luck of the batter, and more on the combined tendency of the batter to be selective of pitches, get his pitch to hit, or take a walk - either way, they're getting on base.

This statistic is the reason we do not like Torre's decision to hit Giambi 5th.  In 2005, Giambi had an OBP of .440, meaning he reached base during 44% of his plate appearances.  This was the best percentage in the American League.

If he is getting on base so often, we would rather see Alex Rodriguez or Gary Sheffield (or both) hitting behind him instead of Matsui and Posada.  He is more likely to score with better hitters behind him, which would better utilize his superior ability to reach base.
 

03.28.2006 NoMaas Stats 101: Batting Average

This is the first entry in what will probably be a long series.  We have decided to take a look at various baseball statistics and break them down to the core.

We are doing this for two main reasons.  The first is to perhaps introduce some of you to statistics that you may not be aware of and explain them in a way that is clear and easy to comprehend.  The second is to help you better understand where we derive our arguments and opinions.

In our first edition of NoMaas Stats 101, we will examine Batting Average:

Batting Average (Known as: AVG, BAV, OBAV...):

Formula: H / AB ~ Hits divided by At-Bats.

Pros: Provides a brief, quaint snapshot of a the percentage of at-bats that a player managed to get converted to a hit. Common enough so that ordinary followers and players of the game will know what it is (although not necessarily know how to interpret it as such). Can be compared to other baseline metrics to determine how lucky or unlucky a batter was on balls in play (BIP).

Cons: Not necessarily a measure of any skill that a batter has. Varies randomly and wildly based on the defense of the opposition, the quality of the opposing pitching, the park played in, and the tendancies of the scorekeepers to reward hits on challenging hit/error calls. Because batting average is dependent on so many things outside of the hitter's control, determining how relevant it is to a player's skill is difficult.  It also does not measure a player's overall ability to get on base which is how runs are created.

Comments: A .300 hitter (which is traditionally thought of as the dividing line between a "good" and "great" hitter) may not necessarily be good or great. They may really be a .275 hitter, and .025 of the hits he got were against teams with horrible pitching and horrible defense, or maybe have even been entirely from lucky bloop hits. This is why NoMaas discourages using AVG as a stand-alone measure of any kind. By using batting average, you're saying a line drive is the same as a bloop hit, and a home run is the same as a bleeder that the pitcher just couldn't get to on time. You know that isn't the case, so don't use it.