Prospects and long-term potential.
The purpose of the Peak Projection system is to project what a prospect will achieve in his prime - his best three consecutive seasons - given his production, age, level of competition, and the standard baseball player’s development curve.
In the 80’s, Bill James derived his Major League Equivalency formula with the purpose of translating the Double-A and Triple-A performances of Minor League players to the Major League level. These translations proved useful to show if an underappreciated Triple-A veteran would make for a quality Major League player.
However, these equivalencies have little stand-alone value when analyzing younger, less developed prospects. The Peak Projection system adds the age adjustment necessary to make the statistics a valuable tool in prospect analaysis.
The system takes the Major League equivalency concept and builds on it by projecting what the player is on target to achieve in his prime if he develops like the average Major League baseball player.
It is true that not every player develops the same. Magglio Ordonez is one of the best hitters in the game today yet put up unimpressive Minor League numbers. Similarly, Sammy Sosa has taken his game to the next level by evolving from an undisciplined hacker to one of the more patient sluggers in the game.
However, for the majority of players, the standard baseball player’s development curve is a fair representation of their growth.
To test the Peak Projection system and the assumptions it makes, I took Spring Training Magazine’s Top 100 prospect list and calculated the projections for all the hitters who accumulated at least 60 plate appearances in Low A or higher prior to 1994. It is important to note that while I normally adjust the minor league statistics for offensive context and league factors, I do not have that data for early-90’s statistics. Therefore, these are presumably less acurrate than the current projections.
The top prospect list was pared down to 39 batters who fit the criterion - ranging in quality from Carlos Delgado to Howard Battle. The average player was 21-years old. Of these 39 batters, Arquimedez Pozo, Brooks Kieschnick, Howard Battle, D.J. Boston, Chad Mottola, Michael Moore and Steve Gibralter never totaled 150 at bats for a three-year period (rendering their Major League statistics nearly meaningless) - lowering our sample to 32 batters. Out of that group, Pozo (.889 OPS) and Kieschnick (.854 OPS) are the only players to have projections north of D.J. Boston’s .753 OPS. It is safe to say that these two would not have met their projections. For reference’s sake, Pozo was born in the Dominican Republic and the current stringent requirements for proving once’s age upon entering the U.S. did not exist.
Now the actual Major League peak performances for the prospects who accumulated enough Major League playing time was calculated. Each player’s best three consecutive years were averaged. Since the statistics were not park adjusted, seasons in Coors Field were ignored. This came into play only for Todd Hollandsworth and Jeffrey Hammonds.
Results of tests between Projected and Real Peak Performance:
BA OBP SLG OPS
Corr. 0.60 0.71 0.64 0.65
R^2 0.36 0.51 0.41 0.43
RMSE 0.025 0.029 0.068 0.091
MAE 0.019 0.023 0.056 0.074
MAPE 7.3% 6.8% 12.1% 9.1%
Corr. = Correlation Coefficient
r^2 = Square of Corr.
RMSE = Root Mean Squared Error
MAE = Mean Absolute Error
MAPE = Mean Absolute Percentage Error
In comparison, Baseball Prospectus’s annual projections scored a correlation of .704 for OPS in 2001, according to Voros McCracken. Now, as with any projection, the bigger the sample the projection is based on, the more accurate the projection. Each projection is accompanied by a theoretical amount of plate appearances. Each stat line is weighted based on whether it was produced in the lower or upper minors (Single-A or Double-A and Triple-A) and the year it was achieved. A performance in Double-A in 1993 is a more reliable indicator of ability than an equal performance in Single-A in 1990. If these stat lines were created by the same player, the former would get more weight in the projection than the latter.
Therefore, the larger the amount of theoretical plate appearances the more likely the player is to achieve their projection. 18 players had 600 plate appearances - a “full season” of these theoretical PA’s - or more in 1994.
For an abbreviated look:
BA OBP SLG OPS
Corr. 0.76 0.84 0.86 0.86
R^2 0.58 0.71 0.74 0.75
In a less scientific test, Shawn Green was the only above average-great player in the group whose projection of .276 BA/ .329 OBP/ .364 SLG missed the boat completely. 19-year olds Derek Jeter and Johnny Damon, along with an unheralded 20-year old named Edgardo Alfonzo, hit for considerably more power in reality than their projection. However, Jeter and Alfonzo, much like today’s Joe Mauer, still projected to be above average Major Leaguers even without the power surges. Damon projected to be a typical light-hitting leadoff hitter. Also of note, after Alfonzo’s next Minor League season, his projected SLG rose considerably.
The tests had limited samples of 32 and 18 batters which does introduce a margin of error. As I continue to improve the system, I intend to continue to test it on bigger samples. Also, important to note that these players’ statistics were not apart of the sample used to derive the Peak Projection formulas.
1994 Peak Projections
2003 Peak Projections
Chris Reed owns and operates ProspectReport.com as well as contributes to various publications. Check out his site for statistical analysis, player features and reports on the future stars of baseball
Posted: February 28, 2003 at 06:00 AM | 7 comment(s)
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