I'm polishing up the introduction for the 2010 book today. Here are a couple of clips that you might find interesting, particularly those who haven't bought the book in previous years.
GRADES AND WHAT THEY MEAN
Grade A prospects are the elite. They have a good chance of becoming stars or superstars. Almost all Grade A prospects develop into major league regulars, if injuries or other problems don't intervene. Note that is a major "if" in some cases.
Grade B prospects have a good chance to enjoy successful careers. Some will develop into stars, some will not. Most end up spending several years in the majors, at the very least in a marginal role.
Grade C prospects are the most common type. These are guys who have something positive going for them, but who may have a question mark or three, or who are just too far away from the majors to get an accurate feel for. A few Grade C guys, especially at the lower levels, do develop into stars. Many end up as role players or bench guys. Some don't make it at all.
A major point to remember is that grades for pitchers do NOT correspond directly to grades for hitters. Many Grade A pitching prospects fail to develop, often due to injuries. Some Grade C pitching prospects turn out much better than expected.
Also note that there is diversity within each category. I'm a tough grader; Grade C+ is actually good praise coming from me, and some C+ prospects turn out very well indeed., especially ones at lower levels.
Finally, keep in mind that all grades are shorthand. You have to read the full comment for my full opinion about a player, the letter grade only tells you so much. A Grade C prospect in rookie ball could end up being very impressive, while a Grade C prospect in Triple-A is likely just a future role player.
WHAT I DO
My approach is a blend of sabermetrics and traditional scouting. I'm not an original or particularly brilliant sabermatrician, but when you do this long enough you know what to look for. I also respect traditional scouting methods, although I do give them a skeptical eye at times. Some traditionalists look at stat-oriented analysis as "performance scouting," but history shows that, for players in pro ball (especially the higher levels), the statistics become better and better measures of their true worth as prospects, rather than just their perceived physical tools.
Personally I think you have to look at both the numbers and the scouting reports to get a good feel on a player, and seeing the player in person is always very helpful, even indispensable in many cases. In a perfect world I'd get to see every player in this book, but alas I don't have the kind of travel budget or family situation that would allow that. When I can't see a player in person, I'll watch video when available or talk with friends or other sources who have seen him.
EVALUATING POSITION PLAYERS: THE SEVEN SKILLS
Here is how I evaluate position players.
Traditionally, scouts use the "Five Tools" to evaluate position players. These tools are hitting for average, hitting for power, running, throwing, and fielding. It makes sense to look at amateur players in this way, since statistics at the high school and college level can be unreliable due to great variations in the quality and context of competition. But judging players already in professional ball solely by the Five Tool Approach is misleading and can lead to bad results.
I've taken the Five Tool concept and tried to refine it into what I call the Seven Skills. The choice of the word "skill" is deliberate. A hammer is a tool, but knowing what to do with it is a skill. The seven skills in baseball are: controlling the strike zone, hitting for power, hitting for average, offensive speed, fielding range, fielding reliability, and throwing utility.
Strike zone judgment is extremely important. Statistically, we should look at the ratio of walks and strikeouts to at-bats and plate appearances, and walks and strikeouts to each other. Generally, a hitter should have a walk total equal to at least 10 percent of his plate appearances. You can eyeball this by just looking at at-bats and increasing the relevant ratio to at least 12 percent if you like.
The relationship between walks and strikeouts is also important. Some successful hitters don't draw many walks, but most of them don't strike out much, either, making their living on contact. Some successful hitters will strike out a lot, but most of them draw walks as well.
There are few examples of consistently successful hitters who strike out frequently AND don't draw walks. There are a few, but not many. Ideally, we want hitters who draw walks AND make contact, which is usually a sign of extremely good plate discipline. Players like that also tend to be the best prospects.
Players with plate discipline problems often fail to reach their ultimate physical ceilings.