Summary

So, the runs in the main report are for with 1,000 games per leve, 60% win rates, and 95% confidence. I ran the report 10 times for Tic Tac Toe, so see how much variation there is between actual runs. You can see that the number of levels varies between 6 or 7. Given the inherent randomness in the plays, it's apparent that some runs will be just over or just under a threshhold; and that this can have a knock-on effect on the number of levels found.

With longer runs and higher confidence level these discrepancies should eventually disappear; the second table here summarises the results with 10,000 games per level and 99% confidence.

Unfortunately, I don't have the processing capacity to run all reports with the tighter constraints so bear in mind that the comparisons in the main report may be off by a level here or there. That should still be enough to give a reasonable basis for comparison.

Levels	1	2	3	4	5	6	7
7	1	2	5	9	19	50	253
6	1	2	6	12	28	98
6	1	2	6	13	26	81
6	1	2	5	10	26	81
6	1	2	6	12	28	89
7	1	2	5	10	23	55	306
7	1	2	5	9	19	50	230
7	1	2	5	10	21	55	278
6	1	2	6	12	26	89
7	1	2	5	10	21	55	306

10,000 games and 99% confidence:

Levels	1	2	3	4	5	6	7	8
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130
7	1	2	5	9	18	38	130
7	1	2	5	8	16	34	107
8	1	2	5	8	14	28	73	370
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130

Detail (1,000 games 95% confidence)

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	569	124	225	918	0.6566 <= 0.6874 <= 0.7165	54.14	13.51	32.35	7.42
4	UCT (its=5)	574	113	291	978	0.6142 <= 0.6447 <= 0.6741	52.35	11.55	36.09	6.98
8	UCT (its=9)	577	107	312	996	0.6026 <= 0.6330 <= 0.6624	57.33	10.74	31.93	6.66
16	UCT (its=19)	554	153	291	998	0.6014 <= 0.6318 <= 0.6611	62.42	15.33	22.24	6.59
26	UCT (its=50)	470	321	179	970	0.6194 <= 0.6500 <= 0.6794	54.12	33.09	12.78	7.02
43	UCT (its=253)	323	616	59	998	0.6019 <= 0.6323 <= 0.6616	36.37	61.72	1.90	7.86
52	UCT (its=596)	60	920	20	1000	0.4890 <= 0.5200 <= 0.5508	8.00	92.00	0.00	8.84
53	UCT (its=596)	13	979	8	1000	0.4716 <= 0.5025 <= 0.5334	2.10	97.90	0.00	8.96

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	575	111	230	916	0.6576 <= 0.6883 <= 0.7175	53.28	12.12	34.61	7.42
5	UCT (its=6)	583	96	255	934	0.6449 <= 0.6756 <= 0.7048	56.10	10.28	33.62	6.93
11	UCT (its=12)	574	113	282	969	0.6201 <= 0.6507 <= 0.6800	62.75	11.66	25.59	6.55
20	UCT (its=28)	530	201	244	975	0.6161 <= 0.6467 <= 0.6760	62.46	20.62	16.92	6.64
33	UCT (its=98)	400	461	130	991	0.6058 <= 0.6362 <= 0.6656	46.12	46.52	7.37	7.41
51	UCT (its=542)	195	781	24	1000	0.5547 <= 0.5855 <= 0.6156	21.50	78.10	0.40	8.41
52	UCT (its=542)	15	969	16	1000	0.4686 <= 0.4995 <= 0.5304	3.10	96.90	0.00	8.94

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	574	114	218	906	0.6658 <= 0.6965 <= 0.7255	52.32	12.58	35.10	7.34
5	UCT (its=6)	579	103	231	913	0.6598 <= 0.6906 <= 0.7197	54.87	11.28	33.84	6.91
12	UCT (its=13)	578	105	275	958	0.6275 <= 0.6581 <= 0.6875	62.84	10.96	26.20	6.58
19	UCT (its=26)	532	197	249	978	0.6142 <= 0.6447 <= 0.6741	63.09	20.14	16.77	6.56
31	UCT (its=81)	420	421	137	978	0.6142 <= 0.6447 <= 0.6741	48.67	43.05	8.28	7.32
50	UCT (its=493)	230	742	28	1000	0.5703 <= 0.6010 <= 0.6309	25.40	74.20	0.40	8.24
51	UCT (its=493)	38	940	22	1000	0.4770 <= 0.5080 <= 0.5389	6.00	94.00	0.00	8.88

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	566	129	268	963	0.6241 <= 0.6547 <= 0.6841	52.75	13.40	33.85	7.41
4	UCT (its=5)	561	139	281	981	0.6122 <= 0.6427 <= 0.6721	49.95	14.17	35.88	7.03
9	UCT (its=10)	576	109	289	974	0.6168 <= 0.6473 <= 0.6767	57.91	11.19	30.90	6.61
19	UCT (its=26)	548	166	246	960	0.6267 <= 0.6573 <= 0.6866	61.56	17.29	21.15	6.58
31	UCT (its=81)	422	417	147	986	0.6090 <= 0.6395 <= 0.6688	48.88	42.29	8.82	7.29
52	UCT (its=596)	240	734	26	1000	0.5764 <= 0.6070 <= 0.6368	25.80	73.40	0.80	8.21
53	UCT (its=596)	18	967	15	1000	0.4706 <= 0.5015 <= 0.5324	3.30	96.70	0.00	8.93

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	575	112	263	950	0.6336 <= 0.6642 <= 0.6935	52.00	11.79	36.21	7.39
5	UCT (its=6)	568	125	259	952	0.6316 <= 0.6623 <= 0.6916	53.36	13.13	33.51	6.85
11	UCT (its=12)	580	101	295	976	0.6155 <= 0.6460 <= 0.6754	62.70	10.35	26.95	6.52
20	UCT (its=28)	521	220	256	997	0.6025 <= 0.6329 <= 0.6623	61.99	22.07	15.95	6.71
32	UCT (its=89)	419	423	152	994	0.6039 <= 0.6343 <= 0.6637	50.40	42.56	7.04	7.30
51	UCT (its=542)	219	764	17	1000	0.5703 <= 0.6010 <= 0.6309	23.40	76.40	0.20	8.33
52	UCT (its=542)	18	967	15	1000	0.4706 <= 0.5015 <= 0.5324	3.30	96.70	0.00	8.93

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	579	103	231	913	0.6598 <= 0.6906 <= 0.7197	54.33	11.28	34.39	7.34
4	UCT (its=5)	561	139	283	983	0.6109 <= 0.6414 <= 0.6708	50.56	14.14	35.30	7.07
9	UCT (its=10)	579	104	291	974	0.6173 <= 0.6478 <= 0.6772	57.39	10.68	31.93	6.62
18	UCT (its=23)	546	169	269	984	0.6103 <= 0.6408 <= 0.6701	60.26	17.17	22.56	6.58
27	UCT (its=55)	454	354	190	998	0.6019 <= 0.6323 <= 0.6616	53.41	35.47	11.12	7.08
45	UCT (its=306)	325	611	56	992	0.6052 <= 0.6356 <= 0.6650	37.00	61.59	1.41	7.85
50	UCT (its=493)	57	924	19	1000	0.4880 <= 0.5190 <= 0.5498	7.60	92.40	0.00	8.85
51	UCT (its=493)	15	955	30	1000	0.4616 <= 0.4925 <= 0.5235	4.50	95.50	0.00	8.91

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	564	134	206	904	0.6673 <= 0.6980 <= 0.7270	49.23	14.82	35.95	7.44
4	UCT (its=5)	556	149	293	998	0.6014 <= 0.6318 <= 0.6611	49.00	14.93	36.07	7.04
8	UCT (its=9)	580	101	279	960	0.6262 <= 0.6568 <= 0.6861	54.48	10.52	35.00	6.62
16	UCT (its=19)	556	150	277	983	0.6114 <= 0.6419 <= 0.6713	60.53	15.26	24.21	6.57
26	UCT (its=50)	475	311	200	986	0.6090 <= 0.6395 <= 0.6688	56.59	31.54	11.87	6.97
42	UCT (its=230)	327	607	57	991	0.6058 <= 0.6362 <= 0.6656	35.82	61.25	2.93	7.87
51	UCT (its=542)	62	918	20	1000	0.4900 <= 0.5210 <= 0.5518	8.20	91.80	0.00	8.83
52	UCT (its=542)	14	965	21	1000	0.4656 <= 0.4965 <= 0.5274	3.50	96.50	0.00	8.93

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	587	88	233	908	0.6642 <= 0.6949 <= 0.7240	55.40	9.69	34.91	7.34
4	UCT (its=5)	563	136	278	977	0.6153 <= 0.6459 <= 0.6752	50.26	13.92	35.82	7.07
9	UCT (its=10)	583	96	248	927	0.6500 <= 0.6807 <= 0.7099	55.45	10.36	34.20	6.64
17	UCT (its=21)	547	167	270	984	0.6103 <= 0.6408 <= 0.6701	61.59	16.97	21.44	6.60
27	UCT (its=55)	455	351	174	980	0.6129 <= 0.6434 <= 0.6727	52.76	35.82	11.43	7.11
44	UCT (its=278)	327	607	61	995	0.6033 <= 0.6337 <= 0.6630	37.09	61.01	1.91	7.89
51	UCT (its=542)	46	925	29	1000	0.4775 <= 0.5085 <= 0.5394	7.50	92.50	0.00	8.85
52	UCT (its=542)	17	961	22	1000	0.4666 <= 0.4975 <= 0.5284	3.90	96.10	0.00	8.92

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	568	126	241	935	0.6442 <= 0.6749 <= 0.7041	52.19	13.48	34.33	7.40
5	UCT (its=6)	586	90	264	940	0.6406 <= 0.6713 <= 0.7006	54.15	9.57	36.28	6.79
11	UCT (its=12)	573	115	253	941	0.6394 <= 0.6700 <= 0.6993	61.64	12.22	26.14	6.66
19	UCT (its=26)	525	212	263	1000	0.6006 <= 0.6310 <= 0.6604	61.40	21.20	17.40	6.63
32	UCT (its=89)	408	446	124	978	0.6147 <= 0.6452 <= 0.6746	47.24	45.60	7.16	7.36
51	UCT (its=542)	226	757	17	1000	0.5738 <= 0.6045 <= 0.6344	24.20	75.70	0.10	8.30
52	UCT (its=542)	18	958	24	1000	0.4661 <= 0.4970 <= 0.5279	4.20	95.80	0.00	8.92

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	575	112	238	925	0.6515 <= 0.6822 <= 0.7114	53.08	12.11	34.81	7.43
4	UCT (its=5)	573	116	303	992	0.6057 <= 0.6361 <= 0.6655	54.44	11.69	33.87	6.96
9	UCT (its=10)	572	118	256	946	0.6364 <= 0.6670 <= 0.6963	53.38	12.47	34.14	6.65
17	UCT (its=21)	553	155	287	995	0.6033 <= 0.6337 <= 0.6630	63.82	15.58	20.60	6.52
27	UCT (its=55)	466	329	199	994	0.6039 <= 0.6343 <= 0.6637	55.03	33.10	11.87	6.99
45	UCT (its=306)	308	645	43	996	0.6026 <= 0.6330 <= 0.6624	33.53	64.76	1.71	7.96
51	UCT (its=542)	59	921	20	1000	0.4885 <= 0.5195 <= 0.5503	7.90	92.10	0.00	8.84
52	UCT (its=542)	19	962	19	1000	0.4691 <= 0.5000 <= 0.5309	3.80	96.20	0.00	8.92

Detail (10,000 games 99% confidence)

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	5530	1194	2410	9134	0.6580 <= 0.6708 <= 0.6833	53.55	13.07	33.38	7.37
4	UCT (its=5)	5527	1199	3008	9734	0.6167 <= 0.6294 <= 0.6419	51.66	12.32	36.02	6.99
8	UCT (its=9)	5609	1035	2958	9602	0.6253 <= 0.6380 <= 0.6506	55.69	10.78	33.53	6.69
15	UCT (its=18)	5354	1545	3078	9977	0.6014 <= 0.6141 <= 0.6265	62.52	15.49	21.99	6.58
23	UCT (its=38)	4640	2973	2346	9959	0.6025 <= 0.6152 <= 0.6277	57.62	29.85	12.53	6.90
36	UCT (its=130)	3406	5441	1148	9995	0.6003 <= 0.6130 <= 0.6254	41.77	54.44	3.79	7.69
62	UCT (its=1547)	1170	8826	4	10000	0.5455 <= 0.5583 <= 0.5710	11.72	88.26	0.02	8.69
63	UCT (its=1547)	4	9989	7	10000	0.4870 <= 0.4999 <= 0.5127	0.11	99.89	0.00	9.00

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	5517	1220	2356	9093	0.6610 <= 0.6738 <= 0.6863	52.81	13.42	33.77	7.41
4	UCT (its=5)	5533	1188	2984	9705	0.6186 <= 0.6313 <= 0.6438	52.01	12.24	35.74	6.98
8	UCT (its=9)	5603	1047	2964	9614	0.6245 <= 0.6372 <= 0.6498	56.02	10.89	33.09	6.66
15	UCT (its=18)	5367	1519	3046	9932	0.6042 <= 0.6168 <= 0.6293	62.33	15.29	22.37	6.58
23	UCT (its=38)	4727	2799	2336	9862	0.6086 <= 0.6212 <= 0.6337	59.19	28.38	12.43	6.85
36	UCT (its=130)	3401	5451	1071	9923	0.6048 <= 0.6174 <= 0.6299	41.42	54.93	3.65	7.70
61	UCT (its=1406)	1237	8756	7	10000	0.5487 <= 0.5615 <= 0.5742	12.42	87.56	0.02	8.67
62	UCT (its=1406)	4	9988	8	10000	0.4869 <= 0.4998 <= 0.5127	0.12	99.88	0.00	9.00

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	5504	1185	2497	9186	0.6539 <= 0.6637 <= 0.6733	54.37	12.90	32.73	7.37
4	UCT (its=5)	5499	1196	2972	9667	0.6210 <= 0.6307 <= 0.6403	52.18	12.37	35.45	7.00
7	UCT (its=8)	5574	1045	3278	9897	0.6064 <= 0.6160 <= 0.6255	55.88	10.56	33.57	6.70
13	UCT (its=14)	5448	1297	3233	9978	0.6014 <= 0.6110 <= 0.6205	61.64	13.00	25.37	6.56
20	UCT (its=28)	4933	2328	2727	9988	0.6008 <= 0.6104 <= 0.6200	61.45	23.31	15.24	6.72
30	UCT (its=73)	3911	4371	1612	9894	0.6066 <= 0.6162 <= 0.6257	48.17	44.18	7.65	7.36
47	UCT (its=370)	2657	6879	393	9929	0.6044 <= 0.6140 <= 0.6235	29.93	69.28	0.79	8.12
61	UCT (its=1406)	229	9767	4	10000	0.5015 <= 0.5112 <= 0.5210	2.33	97.67	0.00	8.95
62	UCT (its=1406)	5	9989	6	10000	0.4902 <= 0.5000 <= 0.5097	0.11	99.89	0.00	9.00

Match	AI	Strong Wins	Draws	Strong Losses	#Games	Strong Score	p1 Win%	Draw%	p2 Win%	Game Length
0	Random
1	UCT (its=2)	5534	1185	2399	9118	0.6591 <= 0.6719 <= 0.6844	53.40	13.00	33.60	7.40
4	UCT (its=5)	5528	1198	2855	9581	0.6268 <= 0.6395 <= 0.6520	51.79	12.50	35.71	6.99
7	UCT (its=8)	5619	1016	3248	9883	0.6073 <= 0.6200 <= 0.6324	55.23	10.28	34.49	6.70
14	UCT (its=16)	5494	1265	2986	9745	0.6160 <= 0.6287 <= 0.6412	62.57	12.98	24.45	6.53
22	UCT (its=34)	4802	2649	2531	9982	0.6011 <= 0.6138 <= 0.6262	59.91	26.54	13.55	6.80
34	UCT (its=107)	3533	5187	1252	9972	0.6017 <= 0.6144 <= 0.6268	42.76	52.02	5.22	7.62
62	UCT (its=1547)	1622	8372	6	10000	0.5680 <= 0.5808 <= 0.5935	16.27	83.72	0.01	8.53
63	UCT (its=1547)	7	9989	4	10000	0.4873 <= 0.5001 <= 0.5130	0.11	99.89	0.00	9.00

Levels	1	2	3	4	5	6	7
7	1	2	5	9	19	50	253
6	1	2	6	12	28	98
6	1	2	6	13	26	81
6	1	2	5	10	26	81
6	1	2	6	12	28	89
7	1	2	5	10	23	55	306
7	1	2	5	9	19	50	230
7	1	2	5	10	21	55	278
6	1	2	6	12	26	89
7	1	2	5	10	21	55	306

Levels	1	2	3	4	5	6	7	8
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130
7	1	2	5	9	18	38	130
7	1	2	5	8	16	34	107
8	1	2	5	8	14	28	73	370
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130

Levels	1	2	3	4	5	6	7
7	1	2	5	9	19	50	253
6	1	2	6	12	28	98
6	1	2	6	13	26	81
6	1	2	5	10	26	81
6	1	2	6	12	28	89
7	1	2	5	10	23	55	306
7	1	2	5	9	19	50	230
7	1	2	5	10	21	55	278
6	1	2	6	12	26	89
7	1	2	5	10	21	55	306

Levels	1	2	3	4	5	6	7	8
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130
7	1	2	5	9	18	38	130
7	1	2	5	8	16	34	107
8	1	2	5	8	14	28	73	370
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130

Levels	1	2	3	4	5	6	7
7	1	2	5	9	19	50	253
6	1	2	6	12	28	98
6	1	2	6	13	26	81
6	1	2	5	10	26	81
6	1	2	6	12	28	89
7	1	2	5	10	23	55	306
7	1	2	5	9	19	50	230
7	1	2	5	10	21	55	278
6	1	2	6	12	26	89
7	1	2	5	10	21	55	306

Levels	1	2	3	4	5	6	7	8
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130
7	1	2	5	9	18	38	130
7	1	2	5	8	16	34	107
8	1	2	5	8	14	28	73	370
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	8	16	34	107
7	1	2	5	9	18	38	130