Table 2. Errors in clade frequencies between observed and predicted values by forecast horizon (in months) and submission lag for A/H3N2 clades with an initial frequency ≥10% under the given lag scenario.

		Clade frequency error (%)					Absolute frequency error (%)
Horizon	Lag type	Mean	Median	SD	Min	Max	Mean	Median	SD
3	None	1	0	9	–28	28	7	6	6
3	Ideal	1	0	11	–32	36	8	6	7
3	Realistic	1	0	13	–31	50	10	7	9
6	None	1	0	17	–48	45	12	9	11
6	Ideal	1	0	19	–50	53	13	9	13
6	Realistic	1	0	20	–52	75	15	12	14
9	None	0	-1	23	–66	59	16	10	17
9	Ideal	1	-1	25	–67	58	18	11	18
9	Realistic	1	-1	26	–67	79	19	12	19
12	None	0	0	30	–82	76	20	10	22
12	Ideal	1	0	31	–80	74	21	9	23
12	Realistic	0	0	31	–78	78	20	12	23