Hardest legendary to capture?
For me it's definitely Moltres. I'm 4/17~24% on Moltres captures and did 8 raids in a row where he escaped. #2 is Articuno, where I am 10/30~33%. This is followed by Lugia (9/14~64%) and the easiest, Zapdos (7/9~78%).
Although I have improved my technique at the start, it is strange to me that I use exactly the same technique on Moltres and Zapdos, with entirely different success rates. With both these I usually have at least 8 Great throws and I always use a golden razz. I freeze the circle and then throw after he attacks, and I take my time. But Moltres almost always escapes my Great throws.
Answers
I've caught 6 of my last 7 Zapdos the past two days...the one I missed was 1839 and might have tossed it anyway. My grand total for Lugia was 2 out of 8. 4 for 6 Articuno. Got a bunch of Moltres, one time 6 in a row. Lugia toughest for me.****Equal note: caught my last 3 Tyranitar. Gives me a full team of 6 big guys
My legendary stats:
Lugia: 2/10
Just awful. I can reliably hit great throws on Lugia, it just always seems to escape. Best Lugia is 14-15-11 (89%). Would like to find one with 15 attack, but Lugia raids are rare here and sometimes hard to get enough people to come to. If I don't get a better one I'll power that one up to level 30.
Articuno: 5/11
Again, pretty reliable great throws. Far better catch rate than Lugia. Still far from great though. Best is either a 12/13/14 (87%) or a 14/15/13 (82%). Again, would really like a 15 attack, but too late for that. Will power one of those up to level 30 soon.
Moltres: 2/5
I was very busy that week, so hard to find time for raids. Fortunately I did get a 89% with 15 attack, so I'll power that one up to L30.
Zapdos: 8/15
My best catch rate is for Zapdos even though I have trouble landing great throws on him. Zapdos raids have been really popular regularly turning out huge crowds so I've done quite a bunch of them. Unfortunately the two best ones I have encountered (both close to 100%) escaped me. I do have a 15/11/15 at 91%, so unless I catch a better one that gets powered up to L30. I might even also power up my second best Zapdos (15/14/12 also at 91%) since he could be quite useful.
EDIT: Total 17/41. Pretty bad overall catch rate.
EDIT: Missed my last 5 or 6 Tyranitars in a row.
Articuno and Lugia were by far the toughest for me. I caught 2 out of 11 for Aritcuno, 2 out of 9 for Lugia, 4 out of 6 for Moltres, and 3 out of 4 for Zapdos so far.
That is counting 1 Lugia and 2 articuno raids when the game crashed and didn't let me try to catch them, but still.
Articuno just would not stay in the ball. I'd hit great throw curve balls almost every throw, sometimes excellent, but it just kept breaking out over and over, even though I usually had 10 or 11 tries.
Lugia gave me the most trouble hitting it in the first place. Constantly dodging all over the place, and when I tried my usual method of waiting for it to attack before I threw, the ball often just fell to the ground uselessly, for no apparent reason, even though I threw it just like normal. So for several of them, I just tried throwing it at normal moments when the bird wasn't doing anything, which usually resulted in a dodged or deflected ball. I had a couple Lugia where I only even hit the thing like three times out of 10 throws. Even once it was working again to throw during its attack sequence, it would frequently jump instantly into a 2nd attack or fly higher into the air to dodge me anyway, in the fraction of the second before the ball would have hit. None of the other birds gave me so much trouble simply hitting them at all. Fortunately, I finally got a good one just yesterday, when I got lucky and caught a 95%er on my first throw.
Moltres gave me no real problems, so that was a nice change of pace after the other two. I think the two that got away were largely because they were weak, so I was feeding them Pinap berries.
The biggest problem I've had with Zapdos is simply finding the raids in the first place. It seems like there have been fewer of those than there were for the other types, and I didn't even get a chance to fight one until the 4th day they were around. Before that, the only one I even saw was at 8 AM, when not enough people were around to fight it.