Of the 126 world team spots up for grabs this year, 17 potential qualifiers are still waiting for their official invitations due to he or she not hitting the IAAF standard. Most of those 17 U.S. athletes without the standard are in the field/racewalk events. This got us thinking, which world standard is the hardest to achieve and which is the easiest?

Below is a chart of the 38 "non-road event" world standards. We were able to rank the difficulty of each standard based on how close the standard is to the 10th-best all-time world mark. We used the 10th-best all-time mark instead of the world record in order to eliminate extreme outliers.

Interestingly, the 10 hardest standards are men's events, and 10 easiest standards are field events.

RNK	SEX	EVENT	% of 10th All-Time	2017 Standard	10th All-Time
1	M	100	0.972	10.12	9.84
2	M	800	0.968	1:45.90	1:42.47
3	M	1500	0.967	3:36.00	3:28.81
4	M	200	0.965	20.44	19.72
5	M	400	0.963	45.50	43.81
6	M	10K	0.960	27:45.00	26:38.76
7	M	110H	0.960	13.48	12.94
8	M	400H	0.960	49.35	47.37
9	M	HJ	0.958	2.30	2.40
10	M	5K	0.958	13:22.60	12:48.77
11	W	100	0.956	11.26	10.76
12	W	1500	0.954	4:07.50	3:56.14
13	W	800	0.953	2:01.00	1:55.26
14	W	100H	0.952	12.98	12.36
15	M	PV	0.947	5.70	6.02
16	W	HJ	0.946	1.94	2.05
17	W	5K	0.943	15:22.00	14:29.11
18	W	400	0.941	52.10	49.04
19	W	400H	0.941	56.10	52.79
20	W	3K SC	0.941	9:42.00	9:07.63
21	W	200	0.940	23.10	21.72
22	M	TJ	0.939	16.80	17.90
23	W	PV	0.938	4.55	4.85
24	M	LJ	0.936	8.15	8.71
25	M	3K SC	0.934	8:32.00	7:58.41
26	W	10K	0.934	32:15.00	30:07.15
27	W	TJ	0.928	14.10	15.20
28	W	HT	0.924	71.00	76.83
29	W	LJ	0.923	6.75	7.31
30	M	DEC	0.921	8,100	8,792
31	M	DT	0.912	65.00	71.26
32	M	SP	0.910	20.50	22.52
33	W	JT	0.909	61.40	67.51
34	M	JT	0.908	83.00	91.46
35	M	HT	0.906	76.00	83.93
36	W	HEP	0.900	6,200	6,889
37	W	DT	0.839	61.20	72.92
38	W	SP	0.818	17.75	21.69