Table 4.

Control Population Performance Before and After Index Year^a

	Before Index Year	After Index Year	PValue (Paired Samples Student tTest)b
No. of seasons in MLS	2.69 ± 2.66	2.52 ± 2.50	.811
Games played per season	18.3 ± 5.73	14.5 ± 7.98	.0003
Minutes per game	65.6 ± 18.2	64.7 ± 21.5	.908
Goals per season	2.20 ± 3.93	1.24 ± 1.91	.045
Total shots per season	14.5 ± 12.3	9.72 ± 9.70	.0003
Shots on goal per season	6.34 ± 5.59	3.72 ± 4.20	.00002
Assists per season	1.70 ± 1.32	1.29 ± 1.45	.067
Yellow cards per season	2.75 ± 2.16	2.26 ± 1.67	.055
Red cards per season	0.17 ± 0.29	0.15 ± 0.22	.618
Fouls committed per season	21.1 ± 14.8	16.4 ± 12.5	.029

^aValues are expressed as mean ± standard deviation. MLS, Major League Soccer.

^bStatistically significant differences have a Pvalue < .005.