Overview

While many professional scouts use a "tools" based system to evaluate players, that type of system is difficult for the average fan to use in comparing players. This is especailly true when comparing minor league players, whom most fans don't see at all until they reach the major leagues. This system of evaluation also is plauged by the perception problem. One person always sees something different than another person. The problem is exascerbated when that person is either a fan of the team (and wants his prospects to be the best) or an employee of the team (and NEEDS his prospects to be the best).

The Theory we work with here at DF is that if a player will be an offensive force at the Major League Level it should show up in his minor league statistics if you look at them "correctly". This last point is obviously very important. Only by looking at statistics in the correct way can you gain any real insight into a players potential. The OPES is our shorthand way of looking at offensive prospects. Our hope is that it will allow the average fan to compare intelligently the value and potential of minor league position players. We hope you will find it useful. As always any suggestions for improvement will be appreciated..

How the System Works

The system ranks EVERY position player with more than 200 AB at any full season level of the minor leagues, (Low A or above). Each player is then compared to his league using 5 criteria:

1) his OBA (on-base average)
2) his SLG (slugging percentage)
3) his OPS (on-base average + slugging percentage)
4) his SEC (secondary average)
5) his age relative to the league

For those of you not familiar with Secondary Average, it is a statistcal mesure developed by Bill James which measures a players secondary contributions to his teams offensive performance. It basically measures patience at the plate, power and speed and as such is useful in helping to evaluate a players base of skills. Rickey Henderson/Barry Bonds are examples of the kinds of players who score well on the secondary average scale.

We also use an age scale to determine the optimmum age for a prospect at each level. A player should be no older than:

23 at AAA
22 at AA
21 at A+
20 at A

This scale helps to eliminate players who are performing very well at a level where they are significantly older than their compeittion. For those of you who have trouble with this concept think of it as a College Freshman baseball player playing against the JV highschool team.  At the same time, a player performing well at a level in which they are younger then the rest of the competition is rewarded.

Our scale used to be slightly more liberal than others you will come across, but we believe that this system is more fair to college players who are typically drafted and sign at 21 out of college and therefore are always behind the curve as they move up the rankings.

Players who are more then 3 years older than the optimal age for the league are excluded from the rankings.

Score

The OPES score is calculated by taking a players stats and subtracting them from the corresponding league stats. These give us the Raw scores for each category.  For example:

Player A has an offenive line that looks like this...

.500 OBA
.571 SLG
1.071 OPS
.429 SEC

vs. a league line that looks like this
.376
.339
.715
.275

Obviously this player is performing significantly better than the league averages. The System subtracts the league numers from the players numbers and then uses a formula to calculate the players OA (offensive adjustment). This OA is the value of the players production relative to his league. While the formula by which we calculate OA is our secret, the total OA for this player would have been 20.501.

That means that this players offensive achievements are worth 20.501 points on our scale of evaluation vs the league he was playing in. The context issue is important to remember because all leagues are not created equal. For Example the OPS of the Pacific Coast League (PCL) was .802 in 1999. The OPS of the International League (INT) was.780. It is obvious that a player with a .800 OPS in the International league is performing over the league average while a player with an .800 OPS in the PCL is a below average player.

The next step is to add this adjustement to a baseline number to produce a score. The number we use is 70.000. Why 70? After 5 years of using numbers from 55-75, 70 produced the right spread of players across the categories. Adding the players score to this constant we get a unadjusted score of 90.501.

On our scale which we will discuss in a moment this player would recieve a A- grade and be considered a Very Good Offensive Prospect. However, we have yet to adjust the players score for his relative age. This is a critical part of the evaluation. Two players with the same OA in the same league but years apart in age are not the same caliber of player.

The age adjustement we use is +/- 3 points for every year under/over the opitmum age for each league. So if our hypothetical player was 22 in AA his score would remain 90.501.   If he was 24 in AA with the same numbers, his score would be lowered by six points to 84.501 dropping him to a B prospect on the scale. If he was 20 in AA with the same
numbers, his score would be raised by 6 points to 96.501, moving him up into the rarified air of and A+ prospect. For players who qualify at more than one level, we use the highest level achieved.

Scale

The Official Gradihng Scale:

A+ 96-100 Cant Miss Offensive Prospect
A 92-96 Superior Offensive Prospect
A- 88-92 Very Good Offensive Prospect
B+ 84-88 Good Offensive Prospect
B 80-84 Solid Offensive Prospect
B- 76-80 Above Average Offensive Prospect
C+ 72-76 Average Offensive Prospect
C 68-72 Mediocre Offensive Prospect
C- 64-68 Suspect
D+ 60-64 Not Even a Suspect
D 56-60 Fire that Scout
D- 52-56 Why did we draft him again?
F below 52 Coaching material.

Players who score consistently below 72 on the scale should not be taken seriously as prospects. Each year the number of players below 72 is higher than those above it.

Points

The points ranking you see on the main prospect list is based on the total number of players ranked in the given year. In 2011 1567 total players were ranked. For the Organizational Rankings Points are given only for players whose score is better than a C+.

Other Notes

Things to remember when using this system.

1)The boundaries set up by the system: The system does not rank any player that has not played in a full season minor league the previous season. Every year we are taken to task for not ranking the newest High School draft pick who others have in the top 10. The reason for this should be clear by our focus. We do not partake of the hype other services do when rating prospects. Our goal is to take a players perfromance at full season levels of the minors and give an objective evaluation of his offensive potential relative to his league. This means that certain hot prospects will be missed initially, but will be ranked when they meet the requirements of the system. We also rank players who return to the minors for extended time even after they have lost their Rookie Status unlike other Prospect Services you may be familiar with. I consdier this a positive as it allows fans to use us as a check for other rankings and a basis for discussion on the pluses and minuses of the different types of rankings.

2) The limits of the system: The system does not consider defense at this time...largely because anaylzing defense is such a tricky proposition and would require many weeks just to organizae the data. Please use common sense in examining the system. For Example it should be obvious that when he was in the minor leagues Joe Mauers position and his plus defense made him a very good prospect even if his offensive contribution is not as strong as others who were ranked with him. In the master list we graded him as as the 72nd best offensive player in the minors. That does not mean that his defense and his position did not make him objectively a top 10 prospect. It simply means that given the methods we use we dont have a way to objectively measure how much credit he should get for those contributions. Use the by position rankings in tandem with the overall lists and note that a B graded catching prospect is more rare than a B rated OF or 1B.

3) Remember that any given season the grades you see are a snapshot of what a player is capable of. The top prospects identified by this system are more rightly thought of as the players who had the best seasons in the minors this particular year relative to their league and with age taken into account. Only by looking at a player over several seasons will you get a clearer picture of his true worth. Please use the Elite Players listing for a more complete look at which prospects have maintained their production over time and level to level. It also provides updated ML games played and Win Share Data for all players who maintained a B- or better ranking throughout their minor league carrers.

4) Please make use of the team notes pages to analyze your favorite teams track record with the system. It provides the top Hitting and Pitching prospects for the current season as well as all other C+ or better prospects for the current season in one place. It also lists the top prostects for your team each year from 2002 forward. It is interesting to review these from time to time to see how many sleeper prospects the system has discovered who turned out much better than some of the more hyped prospects who were household names but never amounted to anything in the majors.