## EXPLANATION OF DOSAGEBloodstock Research Information Services, Inc. Dosage is a system that attempts to predict the distance potential of horses based on certain sires in the first four generations of their pedigrees. These certain sires are called Chefs-De-Race (french for "chiefs of the breed."). Chefs are divided into five categories: Brilliant, Intermediate, Classic, Solid, and Professional. The categories correspond to a range of distance potential from Brilliant (highest speed and least stamina) to Professional (lowest speed and greatest stamina). Classic represents the "ideal" balance of speed and stamina. Of the now 190 assigned "chefs", many are assigned to two categories and their points split between those two categories. A chef in the first generation is assigned 16 points, chefs in the second generation eight points, chefs in the third generation four points, and chefs in the fourth generation two points. This is done to account for the lesser influence of chefs farther back in the pedigree, assuming that a grandsire is half as influential as a sire, a great-grandsire half as influential as a grandsire, etc. Three statistics are generated by dosage: a Dosage Profile (DP), a Dosage Index (DI), and a Center of Distribution (CD). Brilliant Intermediate Classic Solid Professional I----------------I-----------------I-------------I-------------I +2.00 +1.00 0.00 -1.00 -2.00 CD attempts to pinpoint the exact point of balance of a horse's pedigree on a seesaw scale between +2.00 (pure brilliant) to -2.00 (pure Professional). The formula is (twice the Brilliant points plus the Intermediate points) minus (twice the Professional points plus the solid points), the sum of which is divided by (total points). The calculation for Alysheba is (two times 12 [24] plus four [28]) minus (two times zero [28] plus two [26]), which (26) is divided by total points (40), or +0.65. So Alysheba has a DI of 2.08 and a CD of 0.65. What does that mean? Literally, the DI means that Alysheba had 2.1 times as much speed as stamina in his pedigree. The CD means that the point of balance of Alysheba's pedigree is just to the Intermediate side of Classic. Breed norms help to interpret these numbers. THE AVERAGE NORTH AMERICAN PEDIGREE HAS 18 TOTAL POINTS. Alysheba has 40 total points. High total points are generally good. The higher the total points, the better the sires are in a pedigree, and the better the horse in question is likely to be. THE NORMS FOR THE MODERN NORTH AMERICAN BREED ARE APPROXIMATELY 2.40 FOR DI AND +0.70 FOR CD. Alysheba's DI and CD are both lower than the norms. That means he has more stamina and less speed than the average horse. The fundamental principle of dosage theory is that the higher the DI and CD, the lower the distance potential of the horse, and conversely, the lower the DI and CD, the higher the distance potential of the horse. More specifically, horses with a DI higher than 4.00 or a CD higher than 1.25 are not supposed to be able to win high-class races at 1 1/4 miles or farther under level weights or weight for age. The Kentucky Derby is a prime example. A DI of 1.00 and/or a CD of 0.00 are supposed to represent the "ideal balance" of speed and stamina in a pedigree. It has been statistically proven though that there is nothing the least bit "ideal" about the racing performances of horses with such "ideal" numbers. A CD is more precise and a better statistical indicator of distance potential than DI. Additionally, the DI's and CD's of horses with low total points (few chefs in their pedigrees) should be interpreted with caution. CHEF-DE-RACE SIRE POINTS 16 8 4 2 (I) (I & C) Polynesian 42 Native Dancer 50 (B) Geisha 43 Raise A Native 61 Case Ace 34 Raise You 46 (C) Lady Glory 34 Alydar (1975) (B) *Nasrullah 40 On-And-On 56 Two Lea 46 Sweet Tooth 65 Ponder 46 Plum Cake 58 Alysheba, B, C Real Delight 49 (B) *Nasrullah 40 Nantallah 53 Shimmer 45 Lt. Stevens 61 =Gold Bridge (Fr) 29 *Rough Shod 2nd 44 =Dalmary (Gb) 31 Bel Sheba (1970) (S) (C) Man O' War 17 War Admiral 34 Brushup 29 Belthazar 60 *Pharamond 2nd 25 Blinking Owl 38 Baba Kenny 28 (B) Brilliant (I) Intermediate (C) Classic (S) Solid (P) Professional DOSAGE PROFILE = 12-4-22-2-0 DOSAGE INDEX = 2.08 CENTER OF DISTRIBUTION = 0.65 B I C S P 12 + 4 + 22 + 2 + 0 = Dosage Profile (total 40 points) B I (1/2 C) 12 + 4 + 11 = 27 _____________________________ ____ = 2.08 Dosage Index 11 + 2 + 0 = 13 (1/2 C) S P (2XB) I S (2XP) total [(2 X 12) + 4 = 28] - [ 2 + (2 X 0) = 2] = 26 [26 Divided by 40] = 0.65 (total divided by DP total points =) Center of Distribution
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