Table 2.

Predicted rates of speed improvement at 6, 10 and 17 furlongs determined from model 2 fitted to datasets. Average yearly improvement is expressed in absolute units (yards s⁻¹ year⁻¹) and as a percentage of speed in the first year of analysis (1850 or 1997).

dataset	years	classes	finishers	distance (furlongs)	average predicted change in speed per year (yards sec−1 year−1)	average predicted change in speed per year (% of 1850 or 1997 speed)
2.1	1850–2012	elite	winners	6	0.013	0.080
				10	0.010	0.065
				17	0.009	0.060
2.2	1997–2012	elite	winners	6	0.020	0.110
				10	0.004	0.020
				17	−0.002	−0.009
2.3	1997–2012	elite	all	6	0.022	0.124
				10	0.004	0.022
				17	0.003	0.016
2.4	1997–2012	all	winners	6	0.011	0.062
				10	0.006	0.037
				17	0.004	0.022
2.5	1997–2012	all	all	6	0.015	0.090
				10	0.011	0.065
				17	0.006	0.034