Prospect Evaluation Primer: The 20-80 Scale

Talent evaluators use several criterion when forecasting a player's future. In our inaugural installment, we take a look at the system of assessing tools known as the 20-80 scale.

It's important to note that evaluating prospects is an artform that is in constant flux. For many many years, scouting techniques had a monopoly in this market. More recently, the advancement and proliferation of statistical analysis techniques have made the picture a little more muddled. While it might seem like this creates a dichotomy of sorts, the various schools of thought can actually be quite complementary. Over the next few Prospect Evaluation Primer articles, we'll review some background into exactly how this is both possible and, in order to get the most complete picture of a player, even necessary.

For now, let's focus on scouting techniques and, more specifically, the often referenced 20-80 scale.

The 20-80 scale can be used for position players or pitchers but, obviously, the tools they measure vary by group. A score of 50 for a particular tool indicates major league average. For a 19 or 20 year old kid to have an average major league tool is high praise, indeed, and is not something to be taken lightly. A plus tool rates as a 60 and a plus plus tool is at least a 70. Tools that rate as an 80 are very rare-- think Adam Dunn's power, Richard Hidalgo's arm or Joey Gathright's speed. Every once in a while, a position player will rate major league average or better across the board. Therein lies the coveted five tool player.

So what exactly are these tools I'm referring to?

Hitting for Average

A prospect's ability to hit for average can be a result of any number of things. He can have a quick, compact swing or he might just have exceptional hand-eye coordination. The Orioles system is thin on prospects that excel in this tool, but the recently promoted Howie Kendrick is one of the most intriguing contact hitters to come along in years.

Hitting for Power

Every individual tool has to be measured in context to the others, but if a top prospect only has one plus tool, it's normally this one. Many power hitters are big and exceptionally strong, but Miguel Tejada is a good example of how far simple bat speed can get you. Nolan Reimold and the recently drafted Billy Rowell are both legitimate 70's and represent the highest power grades in the O's system.


The running tool is pretty self explanatory. It's important to note that this doesn't necessarily correlate to stolen bases or defensive range. This is pure running speed and is, by and large, measured by the time it takes a batter to get from home to first. Times under 4 seconds are exceptional, while a time over 4.5 seconds is downright Giambian.


The fielding tool is more a measure of range and instinct than it is reliability. For middle infielders and outfielders, range is the most important issue. Corner infielders are much more dependent on footwork and quick reactions. Catchers are a breed unto themselves and rely on a breadth of skills; including agility, durability and an ability to handle pitchers. Exceptional defenders in the O's system include Brandon Fahey and Eli Whiteside.

Arm Strength

Like running, arm strength is a pretty self-explanatory tool. It's importance varies by position; with an emphasis on catchers, third basemen and rightfielders. If you get a chance to take in a Keys game, Arturo Rivas has an absolute canon.

Obviously, not all of these tools carry equal weight. They're merely meant to measure individual attributes of a player as a means to painting a more complete picture. Tools can also be projected out or, to put it another way, players can earn a second score based on a ceiling for an individual tool. For instance, a 16 year old international signee who is 6'3 and 170 lbs. is unlikely to have reached his full power potential. As he matures, fills out physically and refines his approach; he could increase his power score several grades.

Pitchers are an entirely different breed, highlighted by their startlingly high attrition rate. It seems like every year, way too many young hurlers succumb to injury or ineffectiveness. They're tools are also much more heavily dependent on one another.

Scouts evaluate pitchers based on the following categories:

Fastball Velocity

Quite simply, how hard a pitcher can consistently throw. Left-handers generally are forgiven an extra mph or two because of their ability to throw with the wrong hand. Daniel Cabrera is an obvious standout here, but don't forget about players like James Hoey, Brandon Erbe and Radhames Liz.

Fastball Movement

Pitchers can throw two varieties of fastballs: four-seamers and two-seamers. Four-seamers are the more common variety and are the faster of the two, but two-seamers generate more movement. Garrett Olson is a good example of a player that does not generate plus velocity, but is able to get batters out (and induce groundballs) with some good life on his fastball

Individual Secondary Pitches

Pitchers can have radically differing arsenals, so it's pointless to have static categories here. But there are certainly some specific points worth making. Sliders are harder than curveballs, but have less break. Pitches caught in between the two, or slurves, are not a good thing and can be the result of inconsistent mechanics or a 3/4 arm slot. Pitchers generally try to adjust by adding break or velocity to such a pitch. The best curveball in the O's system belongs to Garrett Olson, while James Hoey's slider sure is fun to watch. And despite his major league struggles, Sendy Rleal still has one of the better changeups around.


O's fans are getting acquainted with exactly how important comand can be, even in the face of brilliant stuff. Let's take the obvious example in Daniel Cabrera. He has plus velocity and stuff across the board, but the regression of his command has cost him a major league job. If he's to escape Bobby Witt-dom, it will be because of his work in this area.

Even more so than with the various hitting tools, the evaluation of an individual pitching tool is all but meaningless without proper context. Try and explain the effectiveness of Greg Maddux's repertoire without mentioning his uncanny command or how good Johan Santana's fastball and power slider are without bringing up his changeup for a good idea of what I mean.

Tomorrow, we'll discuss some statistical analysis techniques and the difference between a tool and a skill.

Inside The Os Top Stories