D. R. Evans (N7DR)

2024-03-13

Reverse NILs in CQ WW: 2023; 2014 to 2023

The basic notion of reverse NILs (rNILs; or, I suppose, RNILs) is described here, along with a description of a simple script for calculating rNILs for CQ WW contests and the result of applying that code to the contests for 2005. See also the comments at the end of that post. I would be delighted if anyone who spots any errors in the script would inform me.

We can also look at the results for periods of ten years at a time; the only difference in the way that these decadal tables are calculated is that the minimum number of rQSOs is raised from 50 to 250 for tables pertaining to all QSOs and from 25 to 125 for those pertaining to intra-W QSOs. (That is, the value of the variable MIN_QSOs is changed from 50 to 250.)

Here are the results for 2023 and for the period from 2014 to 2023. As in prior years, I refrain from comment on specific calls.

2023 SSB:

Call	Total rQSOs	Total rNILs
K4JPD	1133	1120
RA3XM	1123	905
CA3VAK	889	885
PY2DR	310	305
F8DVD	2372	275
CN3A	16247	261
KE0UI	303	251
NN7CW	2274	224
6Y1V	7891	218
TO5A	7594	206

Call	Total rQSOs	Total rNILs	% rNILs
CA3VAK	889	885	99.6
K4JPD	1133	1120	98.9
PY2DR	310	305	98.4
IU0PXM	112	101	90.2
KE0UI	303	251	82.8
GW0NEC	62	50	80.6
RA3XM	1123	905	80.6
KE2HG	178	125	70.2
9A1EA	98	67	68.4
DO6MRC	224	103	46.0

Call	Total rQSOs with Ws	rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws
K4JPD	45	45	1088	1075
N2IC	187	34	2091	17
NN7CW	81	28	2193	196
K3LR	616	25	7900	101
KW7MM	145	24	1237	16
WX3B	269	22	5039	68
K3EST	320	18	2666	41
K5GN	251	10	2517	39
K9RS	47	9	3523	45
W2A	45	9	3099	56

Call	Total rQSOs with Ws	Total rNILs against Ws	% rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws	% rNILs against non-Ws
K4JPD	45	45	100.0	1088	1075	98.8
NN7CW	81	28	34.6	2193	196	8.9
W2A	45	9	20.0	3099	56	1.8
K9RS	47	9	19.1	3523	45	1.3
W7VJ	27	5	18.5	983	6	0.6
N2IC	187	34	18.2	2091	17	0.8
KW7MM	145	24	16.6	1237	16	1.3
K8LX	27	4	14.8	1014	17	1.7
K0MD	37	5	13.5	819	16	2.0
W1RCR	73	7	9.6	1034	19	1.8

2023 CW:

Call	Total rQSOs	Total rNILs
SZ1A	4627	1201
OK2YZ	878	460
W1WEF	1227	296
D4C	16391	229
NA3M	613	211
CN3A	14898	205
EA8RM	7890	194
EF6T	7895	188
VK6T	1503	187
8P5A	7530	186

Call	Total rQSOs	Total rNILs	% rNILs
UT3PA	107	106	99.1
IZ2EJU	105	103	98.1
W6ENZ	184	142	77.2
CM3OR	148	109	73.6
JE1TSD	98	66	67.3
VA3SB	199	122	61.3
OK2YZ	878	460	52.4
6K2ILX	109	57	52.3
JF2WXS	68	35	51.5
JH8CXW	128	63	49.2

Call	Total rQSOs with Ws	rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws
N8OO	82	61	1143	15
NN7CW	87	43	3655	37
N1LN	45	19	2034	22
K0RF	213	18	4593	78
K8LX	91	17	3761	44
AB2E/VP9	1773	15	1534	22
AK1MD	66	15	1405	27
NE3F	44	14	2435	41
NF3R	38	13	1866	17
K1LZ	298	12	9528	95

Call	Total rQSOs with Ws	Total rNILs against Ws	% rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws	% rNILs against non-Ws
N8OO	82	61	74.4	1143	15	1.3
NN7CW	87	43	49.4	3655	37	1.0
N1LN	45	19	42.2	2034	22	1.1
NF3R	38	13	34.2	1866	17	0.9
NE3F	44	14	31.8	2435	41	1.7
K0YR	28	8	28.6	688	10	1.5
N5JJ	25	7	28.0	482	5	1.0
AK1MD	66	15	22.7	1405	27	1.9
K8LX	91	17	18.7	3761	44	1.2
NU4E	29	5	17.2	2113	23	1.1

Looking at the past decade:

2014 to 2023 SSB:

Call	Total rQSOs	Total rNILs
EA2DMH	6876	1662
CN3A	88293	1626
LZ9W	95029	1390
PJ2T	71599	1197
K4JPD	4576	1152
PY2HT	4097	1122
YL2014W	1106	1099
MI0M	3870	1085
YT5A	74353	1051
A73A	55005	1040

Call	Total rQSOs	Total rNILs	% rNILs
YV4GMG	328	327	99.7
CA3VAK	889	885	99.6
YL2014W	1106	1099	99.4
ZZ5Z	297	292	98.3
AA1BU	392	350	89.3
EA8DDS	503	387	76.9
LU9WE	772	559	72.4
YO2MLS	313	224	71.6
RT9X	256	177	69.1
VE2RO	596	397	66.6

Call	Total rQSOs with Ws	rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws
N7DD	549	371	7313	144
KV0Q	753	343	6791	92
K3LR	5319	128	61644	746
N2IC	814	113	12004	97
NY6DX	200	95	5782	93
N9RV	603	86	10147	86
K3EST	1749	85	14376	232
K5TR	3189	76	21987	349
W3LPL	2276	54	44619	600
WX3B	1422	53	25097	343

Call	Total rQSOs with Ws	Total rNILs against Ws	% rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws	% rNILs against non-Ws
N7DD	549	371	67.6	7313	144	2.0
NY6DX	200	95	47.5	5782	93	1.6
KV0Q	753	343	45.6	6791	92	1.4
K9BGL	128	49	38.3	6171	202	3.3
K4JPD	138	52	37.7	4438	1100	24.8
KW7MM	145	24	16.6	1238	16	1.3
AB4B	143	22	15.4	5674	64	1.1
N9RV	603	86	14.3	10147	86	0.8
N2IC	814	113	13.9	12004	97	0.8
W8PR	180	23	12.8	10945	154	1.4

2014 to 2023 CW:

Call	Total rQSOs	Total rNILs
SZ1A	42118	1806
LZ9W	107972	1382
PJ2T	93729	1374
P33W	80892	1175
IK3UNA	12883	1138
YT5A	91834	1050
9A1A	89257	1035
JA3YBK	49387	1019
TI7W	52256	1018
CS2C	11967	1010

Call	Total rQSOs	Total rNILs	% rNILs
RZ9CJ	462	460	99.6
OK1KZ	830	712	85.8
WB0CFF	430	313	72.8
XF1IM	702	385	54.8
W2ANQ	320	174	54.4
YS1MS	433	232	53.6
PP5BLU	305	148	48.5
OM2IV	800	372	46.5
F6GOE	1392	645	46.3
TA1FA/2	397	181	45.6

Call	Total rQSOs with Ws	rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws
N7DD	372	192	8764	164
K0RF	2191	161	32869	412
NR5M	1207	130	14698	141
KV2K	393	118	19912	333
NN7CW	988	110	19280	212
N8OO	161	103	3013	26
N9RV	763	82	18904	192
NA3M	190	82	12050	303
K3LR	3289	74	68058	584
WJ9B	837	74	13933	131

Call	Total rQSOs with Ws	Total rNILs against Ws	% rNILs against Ws	Total rQSOs with non-Ws	rNILs against non-Ws	% rNILs against non-Ws
N8OO	161	103	64.0	3013	26	0.9
N7DD	372	192	51.6	8764	164	1.9
NA3M	190	82	43.2	12050	303	2.5
AK1MD	146	45	30.8	4173	115	2.8
KV2K	393	118	30.0	19912	333	1.7
K8LX	288	71	24.7	11738	128	1.1
NE3F	252	60	23.8	16112	268	1.7
KZ5D	243	57	23.5	10793	140	1.3
W5ZN	213	48	22.5	4538	48	1.1
KV0Q	200	43	21.5	1930	63	3.3

2024-03-10

Busting Calls: CQ WW 2023

Prior posts in this series:

Throughout this post, I apply the procedures developed in the second post above.

For the purpose of this post, only verified QSOs are counted.

Lowest Probability

I begin with an ordered list of the stations with the lowest probabilities of busting a call in 2023 CQ WW SSB.

2023 CQ WW SSB -- weighted mean values of $p_{bust}$ (all)
Position	Call	weighted mean	$Q_v$	$B$
1	G0MTN	0.0004	2,056	0
2	DL1NEO	0.0009	1,069	0
3	W9MR	0.0009	1,061	0
4	KW1X	0.0010	910	0
5	W1TC	0.0012	821	0
6	ES2MC	0.0012	790	0
7	N4PQX	0.0013	747	0
8	HA1BB	0.0014	709	0
9	W4EEY	0.0014	693	0
10	OE6MDF	0.0015	2,044	2

And for 2023 CQ WW CW:

2023 CQ WW CW -- weighted mean values of $p_{bust}$ (all)
Position	Call	weighted mean	$Q_v$	$B$
1	DM2M	0.0005	1,850	0
2	W3KB	0.0007	1,281	0
3	JG1LFR	0.0008	1,125	0
4	OR2F	0.0008	2,366	1
5	DL6RDR	0.0009	1,108	0
6	N2GC	0.0010	2,091	1
7	AD1C	0.0010	945	0
8	SN5J	0.0010	1,966	1
9	UX1VT	0.0010	914	0
10	DK5TX	0.0011	1,790	1

It is interesting to plot the aggregated probability function for $p_{bust}$ weighted by the verified number of QSOs, $Q_v$, for all stations:

In case it isn't clear, the location of the solid vertical lines represent the weighted means of the probability curves. In 2023, then, there was essentially no difference between these curves for CW and SSB.

We can limit the analysis to calling stations (i.e., not the running station).

2023 CQ WW SSB -- weighted mean values of $p_{bust}$ (no-run)
Position	Call	weighted mean	$Q_v$	$B$
1	G0MTN	0.0007	1,362	0
2	NJ4P	0.0007	1,295	0
3	DL1NEO	0.0009	1,067	0
4	W9MR	0.0009	1,014	0
5	KW1X	0.0010	908	0
6	PC3M	0.0011	846	0
7	OK6T	0.0011	1,750	1
8	W1TC	0.0012	815	0
9	VE9AA	0.0013	728	0
10	HA1BB	0.0014	705	0

2023 CQ WW CW -- weighted mean values of $p_{bust}$ (no-run)
Position	Call	weighted mean	$Q_v$	$B$
1	DM2M	0.0006	1,445	0
2	K3WJV	0.0007	1,299	0
3	SP9XCN	0.0008	1,161	0
4	LA8OM	0.0008	1,124	0
5	W3KB	0.0009	1,079	0
6	DL6RDR	0.0009	1,024	0
7	N2GC	0.0009	1,016	0
8	K9NW	0.0009	1,015	0
9	K1ZZ	0.0010	995	0
10	M6W	0.0010	2,073	1

And similarly for running stations.

2023 CQ WW SSB -- weighted mean values of $p_{bust}$ (run)
Position	Call	weighted mean	$Q_v$	$B$
1	OL0W	0.0009	1,043	0
2	MM1E	0.0010	956	0
3	G0MTN	0.0014	694	0
4	VE6BBP	0.0017	563	0
5	DL8OBF	0.0019	514	0
6	SP9XCN	0.0019	500	0
7	K3CT	0.0020	482	0
8	9K2HN	0.0021	1,923	3
9	BV2A	0.0023	426	0
10	KU2M	0.0023	862	1

2023 CQ WW CW -- weighted mean values of $p_{bust}$ (run)
Position	Call	weighted mean	$Q_v$	$B$
1	E72U	0.0010	941	0
2	OR2F	0.0012	1,714	1
3	DJ3RA	0.0016	607	0
4	N2GC	0.0019	1,075	1
5	K1ZZ	0.0019	2,670	4
6	WB4TDH	0.0019	499	0
7	AH6KO	0.0021	1,413	2
8	OQ5M	0.0022	1,390	2
9	W8FJ	0.0022	1,840	3
10	N3NR	0.0023	417	0

We can also look at the changes over the period from 2005 to 2023.

First for all QSOs:

Then for calling stations:

And for running stations:

The clear up-tick on CW in 2023 is rather interesting. At first, I thought that it might be due to people logging calls mis-spotted on the various spotting networks. But its presence when one limits the analysis to running stations would seem to make that theory untenable. Perhaps it is due to an increase in entrants using code readers, although one would expect few runners to be using those. So this might be an interesting area for further analysis, should anyone be interested. It really is a quite remarkable year-on-year change.

I think it's also interesting to see who appears to have the lowest probability of busting a call over an extended period. So, for the last ten years:

2014--2023 CQ WW SSB -- weighted mean values of $p_{bust}$ (all)
Position	Call	weighted mean	$Q_v$	$B$
1	NW5Q	0.0005	1,971	0
2	IZ4JMA	0.0005	1,705	0
3	ES2MC	0.0006	3,570	1
4	OZ6AGX	0.0006	1,578	0
5	EW1IP	0.0006	1,495	0
6	OH6GDX	0.0006	1,437	0
7	OH7GGX	0.0007	3,094	1
8	IK4OMU	0.0007	1,376	0
9	IK1PMR	0.0007	2,813	1
10	W4EE	0.0008	1,224	0

2014--2023 CQ WW CW -- weighted mean values of $p_{bust}$ (all)
Position	Call	weighted mean	$Q_v$	$B$
1	NW0M	0.0002	3,875	0
2	N7IR	0.0003	2,558	0
3	AD1C	0.0004	5,676	1
4	WB4TDH	0.0004	5,437	1
5	K6WSC	0.0004	5,134	1
6	KM3T	0.0005	1,966	0
7	K9PW	0.0005	1,947	0
8	JR3RWB	0.0005	1,892	0
9	DP4X	0.0005	4,132	1
10	SE6N	0.0005	4,055	1

A good argument can be made that a better measure of copying ability is to consider only run QSOs:

2014--2023 CQ WW SSB -- weighted mean values of $p_{bust}$ (run)
Position	Call	weighted mean	$Q_v$	$B$
1	F4FTA	0.0009	1,098	0
2	DL7URH	0.0010	928	0
3	C6ARW	0.0010	1,925	1
4	ES2MC	0.0011	1,802	1
5	LU1FAM	0.0011	1,765	1
6	CF7RR	0.0013	1,557	1
7	DL8RDL	0.0013	734	0
8	R7MM	0.0013	728	0
9	VA7RR	0.0015	5,494	7
10	K1ZZ	0.0016	605	0

2014--2023 CQ WW CW -- weighted mean values of $p_{bust}$ (run)
Position	Call	weighted mean	$Q_v$	$B$
1	LY3CY	0.0005	1,755	0
2	RW5CW	0.0006	1,431	0
3	WB4TDH	0.0007	3,049	1
4	W3OA	0.0007	1,354	0
5	E72U	0.0008	3,893	2
6	SE6N	0.0008	1,202	0
7	KM3T	0.0008	1,193	0
8	OH6MW	0.0008	2,372	1
9	R2VM	0.0009	1,040	0
10	UA3QAM	0.0010	998	0

Highest Probability

We can also look at the calls associated with the highest probability of busting calls in either the forward or the reverse direction:

2023 SSB -- Most Busts
Position	Call	QSOs	Busts	% Busts
1	CN3A	15,944	276	1.7
2	6Y1V	7,660	228	3.0
3	II9P	6,697	203	3.0
4	CQ8M	5,495	202	3.7
5	LS2D	4,382	194	4.4
6	TO5A	7,390	190	2.6
7	OT5A	7,273	186	2.6
8	HI3LT	4,965	161	3.2
9	PJ2T	8,812	154	1.7
10	CR6K	9,992	149	1.5

2023 CW -- Most Busts
Position	Call	QSOs	Busts	% Busts
1	EA8RM	7,777	307	3.9
2	D4C	16,145	270	1.7
3	TM1A	8,232	246	3.0
4	CN3A	14,689	213	1.5
5	PJ2T	11,532	213	1.8
6	OT7T	9,412	205	2.2
7	II2S	10,153	184	1.8
8	PX2A	7,508	181	2.4
9	HQ9X	8,454	171	2.0
10	RM9A	9,587	167	1.7

2023 SSB -- Highest Percentage of Busts (≥100 QSOs)
Position	Call	QSOs	Busts	% Busts
1	YB1EQI	109	20	18.3
2	BA7JMO	110	18	16.4
3	C31LK	109	17	15.6
4	IS0AGY	105	15	14.3
5	YF4SDF	106	15	14.2
6	UR5ZDZ	213	30	14.1
7	SA6PBW	125	17	13.6
8	CE3TKG	152	20	13.2
9	BG6QLL	100	13	13.0
10	OH1TS	103	13	12.6

2023 CW -- Highest Percentage of Busts (≥100 QSOs)
Position	Call	QSOs	Busts	% Busts
1	IW2OGY	127	26	20.5
2	9M2KDX	113	22	19.5
3	K3GG	154	29	18.8
4	VE4DL	171	32	18.7
5	K9HXO	149	27	18.1
6	AI2U	224	40	17.9
7	EF4F	185	33	17.8
8	LA6M	346	61	17.6
9	SP2EPV	234	41	17.5
10	SM5DNO	112	19	17.0

2023 SSB -- Most Reverse Busts
Position	Call	QSOs	Reverse Busts	% Reverse Busts
1	DF0HQ	9,933	305	3.1
2	9A1A	11,223	277	2.5
3	EA8RM	7,159	260	3.6
4	YT5A	11,767	186	1.6
5	CN3A	15,944	185	1.2
6	CR6K	9,992	163	1.6
7	LZ6V	2,070	163	7.9
8	LU8DPM	2,770	161	5.8
9	EW5A	7,578	158	2.1
10	S53M	5,884	156	2.7

2023 CW -- Most Reverse Busts
Position	Call	QSOs	Reverse Busts	% Reverse Busts
1	UT3NK	528	528	100.0
2	JF1NHD	3,508	429	12.2
3	RM9A	9,587	404	4.2
4	SM0HRP	2,190	387	17.7
5	II2S	10,153	361	3.6
6	DF0HQ	9,526	271	2.8
7	YT5A	11,522	266	2.3
8	RT4F	8,369	260	3.1
9	CN3A	14,689	258	1.8
10	K3LR	9,083	252	2.8

2023 SSB -- Highest Percentage of Reverse Busts (≥100 QSOs)
Position	Call	QSOs	% Reverse Busts
1	DX3EVM	320	15.6
2	UA3R	191	14.7
3	DU1QVK	190	13.2
4	BG7SSK	146	11.0
5	KE7NGO	174	10.9
6	K9CJ	120	10.8
7	BA7MT	195	10.8
8	VK2DG	322	9.9
9	HZ1SK	357	9.8
10	9A5AFF	543	9.8

2023 CW -- Highest Percentage of Reverse Busts (≥100 QSOs)
Position	Call	QSOs	% Reverse Busts
1	UT3NK	528	100.0
2	SQ2RH	102	30.4
3	DF5GO	125	20.8
4	SA5CDO	274	18.6
5	SM0HRP	2,190	17.7
6	CB4EW	117	15.4
7	N5NHJ	325	14.8
8	SQ6MIH	421	14.7
9	SA6AUN	220	14.1
10	K4HQK	296	13.2

In tables of reverse busts, one sometimes finds what seems like an unreasonable number of reverse busts (as is the case, for example, for UT3NK in the 2023 CW table above). This is generally caused by a discrepancy between the call actually sent by the listed station and the one recorded as being sent in at least some QSOs in the station's log. Other causes of frequent reverse busts are poor sending/audio, unusual calls and calls that are very similar to the call of an active, well-known contester.

Looking at a ten-year period:

2014--2023 SSB -- Most Busts
Position	Call	QSOs	Busts	% Busts
1	LZ9W	93,344	1,627	1.7
2	CN3A	86,528	1,534	1.8
3	OT5A	59,537	1,288	2.2
4	PJ2T	70,334	1,231	1.8
5	YT5A	73,097	1,043	1.4
6	V26B	59,233	1,008	1.7
7	A73A	53,842	958	1.8
8	II2S	53,546	905	1.7
9	CR6K	56,086	866	1.5
10	CQ8M	26,546	826	3.1

2014--2023 CW -- Most Busts
Position	Call	QSOs	Busts	% Busts
1	PJ2T	92,331	1,213	1.3
2	LZ9W	106,254	1,138	1.1
3	TK0C	73,216	1,092	1.5
4	YT5A	90,512	904	1.0
5	JA3YBK	48,207	882	1.8
6	PI4CC	42,027	825	2.0
7	EA8RM	32,842	791	2.4
8	ZW8T	11,756	789	6.7
9	HG7T	68,957	763	1.1
10	VY2TT	46,723	757	1.6

2014--2023 SSB -- Highest Percentage of Busts (≥500 QSOs)
Position	Call	QSOs	Busts	% Busts
1	K2JMY	1,278	217	17.0
2	IS0AGY	527	86	16.3
3	YB2BNN	632	87	13.8
4	EA7JQT	572	71	12.4
5	R9MBY	534	63	11.8
6	OH1TS	763	88	11.5
7	EA1HTF	1,762	177	10.0
8	UR5ZDZ	1,107	111	10.0
9	EA4GWL	931	91	9.8
10	EA8DEG	1,125	108	9.6

2014--2023 CW -- Highest Percentage of Busts (≥500 QSOs)
Position	Call	QSOs	Busts	% Busts
1	W2UDT	564	138	24.5
2	4Z5FW	527	108	20.5
3	BD3MV	708	145	20.5
4	DJ5UZ	723	136	18.8
5	SP2EPV	510	93	18.2
6	AE3D	775	140	18.1
7	DL7CO	827	140	16.9
8	CE6VMO	695	111	16.0
9	LZ1BY	789	124	15.7
10	PY1NSC	573	89	15.5

2014--2023 SSB -- Most Reverse Busts
Position	Call	QSOs	Reverse Busts	% Reverse Busts
1	DF0HQ	85,290	2,560	3.0
2	CN3A	86,528	1,178	1.4
3	JA3YBK	33,724	1,115	3.3
4	TM3R	24,257	1,049	4.3
5	K3LR	65,887	977	1.5
6	YT5A	73,097	951	1.3
7	EA8RM	32,239	923	2.9
8	CA3CLF	982	915	93.2
9	IK2YCW	25,411	830	3.3
10	OT5A	59,537	809	1.4

2014--2023 CW -- Most Reverse Busts
Position	Call	QSOs	Reverse Busts	% Reverse Busts
1	DF0HQ	80,526	2,549	3.2
2	JS3CTQ	20,632	2,405	11.7
3	ES9C	59,518	1,862	3.1
4	RM9A	72,978	1,803	2.5
5	HG7T	68,957	1,656	2.4
6	YT5A	90,512	1,560	1.7
7	R2VM	1,426	1,426	100.0
8	K3LR	70,437	1,403	2.0
9	HG6N	47,920	1,361	2.8
10	DR4A	54,247	1,339	2.5

2014--2023 SSB -- Highest Percentage of Reverse Busts (≥500 QSOs)
Position	Call	QSOs	% Reverse Busts
1	CA3CLF	982	93.2
2	PT4Z	1,011	20.3
3	DX3EVM	847	12.2
4	ZP6DYA	963	12.1
5	OG60F	4,258	11.4
6	OA4DKN	511	11.4
7	BH7PCT	846	10.9
8	LU9DDJ	862	10.4
9	HS3PIK	674	9.9
10	BY4DX	1,611	9.9

2014--2023 CW -- Highest Percentage of Reverse Busts (≥500 QSOs)
Position	Call	QSOs	% Reverse Busts
1	R2VM	1,426	100.0
2	UT3NK	528	100.0
3	YT65A	1,149	37.2
4	G3RWF	2,682	35.5
5	5K0A	1,853	32.1
6	PE75W	1,408	29.3
7	OG55W	3,265	28.6
8	TA1C/2	1,513	18.1
9	DP65HSC	516	16.9
10	5J1E	1,523	15.6