Dosage Figures on Dirt vs Turf 2008

Annual Dosage statistics clearly show a differentiation in the figures depending on track surface, with the averages on turf (DI 2.58, CD 0.58) being significantly lower than the averages on dirt (DI 3.59, CD 0.77). At the same time, the average distance of turf races is longer (8.85 furlongs versus 7.76 furlongs), making the lower turf averages consistent with the traditional Dosage model correlating the figures with distance. However, the table below shows that between 6f and 12f, the Dosage figures are lower on turf at every distance. Therefore, the differences observed between the two surfaces can not be attributable exclusively to differences in the average distance of the races. It appears there may be a general, undefined aptitudinal predisposition for turf associated with chefs-de-race assigned to the more stamina-oriented aptitudinal groups. The significance of this observation is that aptitudinal assignments for future chefs-de-race should take into account not only the average winning distance of their progeny, but also the distribution of their wins by surface.

DIST.	SURF.	DP									DI	CD
6.00	DIRT	8.30	-	4.68	-	8.10	-	0.99	-	0.47	4.40	0.88
6.00	TURF	7.18	-	4.18	-	7.80	-	1.12	-	0.46	3.47	0.81
6.50	DIRT	7.87	-	4.31	-	7.69	-	1.06	-	0.52	4.04	0.85
6.50	TURF	7.45	-	3.99	-	9.27	-	1.44	-	0.69	3.20	0.72
7.00	DIRT	8.48	-	4.88	-	9.03	-	1.13	-	0.63	3.85	0.83
7.00	TURF	8.71	-	5.25	-	9.69	-	1.51	-	0.80	3.18	0.75
8.00	DIRT	8.03	-	4.71	-	9.59	-	1.38	-	0.76	3.31	0.75
8.00	TURF	7.02	-	3.99	-	10.99	-	1.73	-	0.84	2.76	0.61
8.50	DIRT	7.51	-	4.53	-	9.58	-	1.29	-	0.80	3.25	0.72
8.50	TURF	7.16	-	4.37	-	10.61	-	1.78	-	0.94	2.74	0.63
9.00	DIRT	7.47	-	4.69	-	9.94	-	1.43	-	0.87	3.11	0.69
9.00	TURF	6.93	-	4.24	-	11.34	-	1.85	-	1.08	2.50	0.57
10.00	DIRT	7.91	-	4.95	-	10.95	-	1.56	-	1.16	2.84	0.66
10.00	TURF	6.69	-	3.98	-	12.25	-	2.25	-	1.71	2.13	0.45
12.00	DIRT	8.28	-	4.56	-	10.94	-	2.14	-	1.21	2.42	0.61
12.00	TURF	6.24	-	3.94	-	11.52	-	2.69	-	1.74	1.98	0.40